ABRASIVE ARTICUE

BACKGROUND ART

Some grinding wheels are made by sequentially charging layers of an abrasive mix and fiber glass web reinforcements into a mold, consolidating the components with pressure, and then subsequently curing in an oven at elevated temperatures. Grinding wheels of this type are generally used for cutting, abrading, and shaping various materials, such as stone, metal, glass, plastics, and other materials. With continued use, the diameter of a grinding wheel constantly decreases, and an operator must continuously adjust the grinding angle in order to maintain a constant material removal rate, while simultaneously preventing the newly formed tapered edge of the wheel from ‘biting-in’ and gouging the workpiece. The industry continues to demand abrasive articles capable of improved performance. SUMMARY

The present invention relates in general to abrasive articles, and in particular, to an abrasive article (e.g., grinding wheel) having improved performance of reduced gouging and an increased range of grinding angle operation.

An embodiment of an abrasive article disclosed herein may include: a body including: a non-abrasive portion (NAP) essentially free of abrasive particles; and an abrasive portion (AP) comprising abrasive particles contained in a bond material; wherein the body comprises a radial thickness difference value (At= Tp/Ti) of at least 1.01, and wherein Ti is the average thickness of the body at an inner annular side surface and Tp is the average thickness of the body at a peripheral side surface.

An embodiment of an abrasive article disclosed herein may include: a body including: a non-abrasive portion (NAP) essentially free of abrasive particles; and an abrasive portion (AP) comprising abrasive particles contained in a bond material; wherein the abrasive portion comprises an average normalized percent theoretical density of not greater than 28%/mm.

An embodiment of an abrasive article disclosed herein may include: a body including: a non-abrasive portion (NAP) essentially free of abrasive particles; and an abrasive portion (AP) comprising abrasive particles contained in a bond material; wherein the body comprises a functional grinding angle within a range of 0 degrees to 90 degrees.

An embodiments of a method of fabricating an abrasive article disclosed herein may include: (a) forming a precursor body including a non-abrasive portion (NAP) and a green abrasive portion (AP); and (b) forming the precursor body into an abrasive article by selectively applying a different force on the green AP as compared to the NAP for at least a portion of the forming process.

An embodiment of a method of conducting a material removal operation disclosed herein may include: moving an abrasive article relative to a workpiece, wherein the abrasive article comprises a body including: a non-abrasive portion (NAP) essentially free of abrasive particles; an abrasive portion (AP) comprising abrasive particles contained in a bond material; and wherein moving the abrasive article relative to the workpiece includes tilting the abrasive article at a functional grinding angle within a range of 0 degrees to 90 degrees. BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the features and advantages of the embodiments are attained and can be understood in more detail, a more particular description may be had by reference to the embodiments thereof that are illustrated in the appended drawings. However, the drawings illustrate only some embodiments and therefore are not to be considered limiting in scope as there may be other equally effective embodiments. Reference herein to an element of any embodiment is a non-limiting embodiment, and disclosure of multiple elements in an embodiment is not to be interpreted as limiting any embodiments herein to any one particular combination of elements.

FIG. 1 is a top view of an abrasive article according to an embodiment of the disclosure.

FIG. 2 is a bottom view of the abrasive article of FIG. 1.

FIG. 3 is a cross-sectional oblique view of a discontinuous fiber of the abrasive article of FIGS. 1 and 2.

FIG. 4 is a cross-sectional side view of the abrasive article of FIGS. 1 and 2.

FIG. 5 is a cross-sectional side view of another abrasive article according to an embodiment of the disclosure.

FIG. 6 is a simplified diagram of functional grinding angles of embodiments of abrasive articles of the disclosure.

FIG. 7 is a flowchart of a method of fabricating an abrasive article according to an embodiment of the disclosure.

FIG. 8 is a flowchart of a method of conducting a material removal operation according to an embodiment of the disclosure.

FIG. 9 is a chart providing comparative data of conventional abrasive articles and embodiments of abrasive articles of the disclosure. FIG. 10 is a graph of the comparative data of the conventional abrasive articles and embodiments of abrasive articles of the disclosure depicted in the chart of FIG. 6.

FIG. 11 is a chart of the comparative data of the conventional abrasive articles and embodiments of abrasive articles of the disclosure depicted in the chart of FIG. 6 and the graph of FIG. 7.

The use of the same reference symbols in different drawings indicates similar or identical items.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to FIGS. 1 and 2, a top view and a bottom view of an abrasive article 100 are shown, respectively, according to an embodiment of the disclosure. Abrasive article 100 may generally comprise a body 102, a central aperture 104 disposed through the body 102, a central axis 106, and an outer wheel diameter 108. The body 102 may comprise a non abrasive portion (NAP) 110 and an abrasive portion (AP) 112.

In an embodiment, the NAP 110 may comprise one or more features and/or dimensions that may facilitate improved manufacturing and/or performance of the abrasive article 100. In some embodiments, the NAP 110 may be free of abrasive particles.

In some embodiments, the NAP 110 may include an organic material, such as phenolic resin, boron-modified resin, nano-particle-modified resin, urea-formaldehyde resin, acrylic resin, epoxy resin, polybenzoxazine, polyester resin, isocyanurate resin, melamine- formaldehyde resin, polyimide resin, other suitable thermosetting or thermoplastic resins, or any combination thereof. In one particular embodiment, the NAP 110 may consist essentially of any one of phenolic resin, boron-modified resin, nano-particle-modified resin, urea- formaldehyde resin, acrylic resin, epoxy resin, polybenzoxazine, polyester resin, isocyanurate resin, melamine-formaldehyde resin, polyimide resin, other suitable thermosetting or thermoplastic resins, or any combination thereof.

For example, in some embodiments, the NAP 110 may include at least 10 vol% of an organic material for a total volume of the NAP 110. In another embodiment, the content of organic material may be greater, such as at least 20 vol%, at least 25 vol%, at least 30 vol%, at least 40 vol%, at least 50 vol%, at least 60 vol%, at least 70 vol%, at least 80 vol% or at least 90 vol%. In some embodiments, the NAP 110 may include not greater than 95 vol% organic material for a total volume of the NAP 110, such as not greater than 90%, not greater than 80%, not greater than 70%, not greater than 60%, not greater than 50%, not greater than 40%, not greater than 30%, or not greater than 20%. It will be appreciated that the content of organic material can be within a range between any of the minimum and maximum percentages noted above, including for example at least 10 vol% to not greater than 95 vol%.

In some embodiments, the NAP 110 may further include one or more fillers contained within the organic material. In some embodiments, the fillers may comprise fibers, particles, bundled fibers, agglomerates, and the like. The fillers may include natural and/or synthetic materials. In one embodiment, the filler may comprise a matrix of discontinuous fibers (120 in FIG. 3) comprising chopped strand fibers (CSF), milled fibers, microfibers, organic fillers, inorganic fillers or any combination thereof.

In some embodiments, the CSF may comprise a pre-formed chopped strand fiber mat. Alternatively, the CSF may be chopped directly into a mold, or pre-chopped, and then added to a mold. In some embodiments, the NAP 110 may comprise at least about 20% by volume (20 vol%) of the CSF for a total volume of the NAP 110, at least about 25 vol%, at least about 30 vol%, or at least about 35 vol%. Further, in some embodiments, the NAP 110 may comprise not greater than about 40 vol% of the CSF for a total volume of the NAP, not greater than about 35 vol%, not greater than about 30 vol%, or not greater than about 25 vol%. It will be appreciated, that the content of the CSF in the NAP can be within a range between any of the minimum and maximum percentages noted above, including for example at least about 20 vol% to not greater than about 40 vol%.

In other embodiments, the NAP 110 may comprise porosity, milled fibers, microfibers, organic fillers, and/or inorganic fillers. The AP 112 comprises an abrasive mixture comprising an organic bond material and a plurality of abrasive particles dispersed throughout the organic bond material. In some embodiments, a discrete layer of CSF may be located at least partially in the organic bond material and coupled (e.g., chemically and mechanically bonded) to the AP 112 for reinforcement thereof. In some versions, the discrete layer can be a sintered mat of the CSF, such that the CSF are integral. Other versions of the abrasive article 100 may comprise at least one continuous fiber reinforcement web in the body 102, such that the body 102 is reinforced by the discontinuous fibers 120 and the continuous fiber reinforcement web. However, in other versions, the body 102 may not have a continuous fiber reinforcement web, such that the body 102 is reinforced only by the discontinuous fibers 120. Further, in some embodiments, the abrasive article 100 may be free of any fibers.

Referring to FIG. 3, an oblique cross-sectional view of a discontinuous fiber 120 is shown according to an embodiment of the disclosure. Discontinuous fiber 120 may generally comprise a chopped strand fiber (CSF). It will be appreciated that the shapes, numbers, and relative sizes of the fibers, filaments, and coatings can vary, depending on the application. Discontinuous fiber 120 may comprise a substantially cylindrical or other rounded cross- sectional shape, such as and oval or elliptical shape. Discontinuous fiber 120 may generally formed from a plurality of multiple individual filaments 122, which may comprise a primary coating 124. Collectively, the individual filaments 122 may be encased within a secondary coating. For example, the CSF can have a direct sized coating, and the thermoplastic coating can be a secondary coating 126 on the direct sized coating 124.

The direct sized coating can have a loss on ignition (LOI), which may be defined as the wt% of the coating relative to the total weight of the CSF. For example, the LOI can be less than about 2 wt%, such as less than or equal to about 1 wt%. Other embodiments of the reinforcement can have a LOI of at least about 2 wt%. In some examples, the LOI can be at least about 3 wt%, such as at least about 5 wt%, at least about 7 wt%, at least about 9 wt%, at least about 12 wt%, or even at least about 15 wt%. Alternate embodiments of the LOI can be not greater than about 25 wt%, such as not greater than about 20 wt%, not greater than about 15 wt%, or even not greater than about 12 wt%. The LOI may be in a range between any of these minimum and maximum values.

Discontinuous fibers 120 may generally comprise a sectional aspect ratio of width (W) to thickness (“T”). The sectional aspect ratio can be in a range of about 1:1 to about 3:1. For example, the sectional aspect ratio may be about 1.75:1 to about 2.75:1, or even about 2:1 to about 2.5:1. In some embodiments, the discontinuous fibers 120 may comprise a width (e.g., a radial width) of at least about 0.1 mm. For example, the radial width may be at least about 0.2 mm, such as at least about 0.3 mm. In other versions, the radial width can be not greater than about 0.5 mm, such as not greater than about 0.4 mm, not greater than about 0.3 mm, or even not greater than about 0.2 mm. Further, in some embodiments, the width may be in a range between any of the minimum and maximum values.

Discontinuous fibers 120 may also comprise an axial length (AL) of at least about 6 mm. In other versions, the axial length may be at least about 7 mm, such as at least about 8 mm, at least about 10 mm, at least about 15 mm, or even at least about 20 mm. In some embodiments, the axial length may be not greater than about 150 mm, such as not greater than about 100 mm, not greater than about 75 mm, not greater than about 50 mm, not greater than about 40 mm, or not greater than about 30 mm. Further, the axial length may be in a range between any of these minimum and maximum values.

Embodiments of the strand of discontinuous fibers 120 may have an aspect ratio of axial length to radial width of at least about 10. For example, the aspect ratio may be at least about 12, such as at least about 25, such as at least about 50, at least about 75, at least about 100, at least about 250, or even at least about 500. In other versions, the aspect ratio can be not greater than about 1500, such as not greater than about 1000, not greater than about 750, not greater than about 500, not greater than about 250, not greater than about 200, or even not greater than about 150. Further, the aspect ratio may be in a range between any of these minimum and maximum values.

Embodiments of the body 102 may comprise a volume percentage of the discontinuous fibers 120 of at least about 1 vol% of organic bond material. For example, the volume percentage of the discontinuous fibers can be at least about 2 vol%, such as at least about 5 vol%, at least about 10 vol%, at least about 15 vol%, at least about 20 vol%, at least about 25 vol%, at least about 30 vol%, or at least about 35 vol%. In some embodiments, the volume percentage of the discontinuous fibers 120 can be not greater than about 50 vol% of organic bond material, such as not greater than 40 vol%, not greater than about 35 vol%, not greater than about 30 vol%, not greater than about 25 vol%, or not greater than about 20 vol%. It will be appreciated that the volume percentage of the discontinuous fibers 120 can be within a range between any of these minimum and maximum values, for example, within a range of at least 1 vol% to not greater than 50 vol% of organic bond material, such as at least about 10 vol% to not greater than 40 vol% or at least 20 vol% to not greater than 40 vol%.

Referring now to FIG. 4, a cross-sectional side view of the abrasive article 100 of FIGS. 1 and 2 is shown according to an embodiment of the disclosure. As stated, abrasive article 100 may comprise a body 102 comprised of the NAP 110 and the AP 112. In the embodiment shown, the NAP 110 comprises a NAP back 110a and a NAP core 110b. In some embodiments, the NAP back 110a and the NAP core 110b may be bonded together. However, in some embodiments, the NAP back 110a and the NAP core 110b may be formed as a unitary, substantially homogeneous component.

In some embodiments, the NAP back 110a and the NAP core 110b are axially aligned along axis 106, such that the aperture 104 is disposed through both of the NAP back 110a and NAP core 110b. In some embodiments, the NAP back 110a and the NAP core 110b comprise substantially similar inner diameters, which collectively define a smooth inner annular surface 128 within the aperture 104. In some embodiments, the NAP back 110a generally comprises a larger outer diameter than the NAP core 110b. In some embodiments, the NAP back 110a may also comprise a greater thickness than the NAP core 110b. Still, in other embodiments such as the embodiment shown, the NAP back 110a and the NAP core 110b comprise substantially similar thicknesses. In some embodiments, the NAP 110 may generally comprise a molding compound (MC), such as a bulk molding compound (BMC) or a sheet molding compound (SMC).

More particularly, the organic material may include bulk molding compound, and even more particularly, the organic material may consist essentially of an SMC, a BMC, or combination thereof. In another embodiment, the organic material may consist essentially of bulk molding compound (BMC) and sheet molding compound (SMC). In still another embodiment, the NAP 110 can include a molding compound, and more particularly, may consist of a molding compound, such as BMC, SMC, or any combination thereof.

In some embodiments, the MC may comprise at least one of a solvent-free liquid phenolic resin resole and a novalac phenolic resin having a melting temperature less than about 90°C, less than about 80°C, less than about 75°C, or less than about 70°C. In some embodiments, the MC may comprise at least one of hexamethylene tetramine (HMTA) and a novalac phenolic resin having a melting temperature at least about 70°C, at least about 75°C, at least about 80°C, at least about 90°C, or at least about 100°C. In some instances, the MC may comprise a thermoset material.

According to at least one embodiment, the MC may comprise a specific gravity that is at least about 1.4, at least about 1.5, at least about 1.6, or at least about 1.7. Additionally, the MC may also comprise a specific gravity that is not greater than about 1.9, not greater than about 1.8, or not greater than about 1.7. The specific gravity of the MC may also be in a range including any of these minimum and maximum values.

Still further, NAP 110 comprises a MOHS scale hardness that is less than about 9. In other embodiments, NAP 110 may comprise a MOHS scale hardness that is less than about 8, less than about 7, less than about 6, or less than about 5. Additionally, NAP 110 may also comprise a MOHS scale hardness that is at least about 1, at least about 2, at least about 3, or at least about 4. The MOHS scale hardness of the NAP 110 may also be in a range including any of these minimum and maximum values.

According to one embodiment, the AP 112 may generally comprise an abrasive mixture comprising an organic bond material and a plurality of abrasive particles dispersed throughout the organic bond material. The AP 112 may be bonded to the NAP 110, and more specifically, at least partially to each of the NAP back 110a and the NAP core 110b. The AP 112 may at least partially define or be associated with a first major surface 114 of the body 102 and at least partially define or be associated with an opposing second major surface 116 of the body 102. The NAP back 110a may define the remainder of the second major surface 116 of the body 102 not defined by the AP 112. As stated, aperture 104 may be disposed through each of the NAP back 110a and NAP core 110b, such that the NAP back 110a and the NAP core 110b define the inner annular surface 128 of the body 102. As such, no portion of the AP 112 defines a portion of the inner annular surface 128. The NAP core 110b may be disposed on an opposing side of the NAP back 110a from the second major surface 116 of the body 102 and at least partially define or be associated with the first major surface 114 of the body 102. The NAP core 100b may also be disposed radially within the AP 112, such that the AP 112 defines the entirety of a peripheral side surface 130 of the body 102. Accordingly, no portion of the NAP back 110a or the NAP core 110b defines the peripheral side surface 130, and no portion of the AP 112 defines the inner annular surface 128.

The abrasive article 100 may also comprise a reinforcing member 118 distinct from the NAP 110 and the AP 112. The reinforcing member 118 may generally comprise a thin layer overlying at least a portion of the body 102 and in contact with and/or overlying at least a portion of the NAP 110 and at least a portion of the AP 112. More specifically, in the embodiment shown, reinforcing member 118 overlies the AP 112 on the first major surface 114 and overlies the NAP 110 and a portion of the AP 112 on the second major surface 116. As such, the thin layer of reinforcing material 118 may generally comprise an average thickness less than an average thickness of each of the NAP 110 and the AP 112.

In some embodiments, the reinforcing member 118 may comprise a continuous glass web. However, in some embodiments, the reinforcing member may comprise a glass, fibers such as CSF, mat, woven material, non-woven material, or any combination thereof. Further, at least in some embodiments, the CSF may be coated with a coating, such as one or more of a thermoplastic, thermoplastic phenolic, phenoxy, polyurethane, and novolac, which may be cross-linked. Furthermore, while reinforcing member 118 may form a thin layer over a portion of the NAP 110 and/or the AP 112, it will be appreciated that dimensions of the reinforcing member 118 are not used in calculating or determining any relative compositions or dimensions of the body 102, the NAP 110, or the AP 112, and/or ratios between the body 102, the NAP 110, and the AP 112 as described herein.

Still referring to FIG. 4, at the inner annular surface 128, the body 102 of the abrasive article 100 may comprise an average thickness (Ti). Along the peripheral side surface 130, the body 102 of the abrasive article may comprise an average thickness (Tp). Additionally, the AP 112 may comprise a peripheral side surface thickness (TAP) as also measured at the peripheral side surface 130. In some embodiments, TAP may comprise at least about 1% of Tp, at least about 3% of Tp, at least about 5% of Tp, at least about 10% of Tp, at least about 20% of Tp, at least about 30% of Tp, at least about 40% of Tp, at least about 50% of Tp, at least about 60% of Tp, at least about 70% of Tp, at least about 80% of Tp, at least about 90% of Tp, or at least about 95% of Tp. However, in some embodiments, TAP may be equal to Tp, such that AP 112 extends for the entirety of the total average thickness of the peripheral side surface.

Abrasive article 100 may further comprise a radial thickness difference value (At=Tp/Ti). In some embodiments, At may be at least 1.01. However, in some embodiments, At may be at least about 1.02, at least about 1.03, at least about 1.04, at least about 1.05, at least about 1.06, at least about 1.07, at least about 1.08, at least about 1.09, at least about 1.10, at least about 1.11, at least about 1.12, at least 1.13, at least about 1.14, at least about 1.15, at least about 1.16, at least about 1.17, at least about 1.18, at least about 1.19, at least about 1.20, at least about 1.21, at least about 1.22, at least about 1.23, at least about 1.24, at least about 1.25, at least about 1.26, at least about 1.27, at least about 1.28, at least about 1.29, or at least about 1.30. Additionally, in some embodiments, At may not be greater than about 5.00, not greater than about 4.00, not greater than about 3.00, not greater than about 2.00, not greater than about 1.90, not greater than about 1.70, or not greater than about 1.50. Further, At may also be in a range between any of these minimum and maximum values, including for example at least about 1.01 and not greater than about 5.00.

Most generally, the body 102 of the abrasive article 100 may comprise an average radial length (RL). Along the first major surface 114 of the body 102 of the abrasive article 100, NAP 110, such as NAP core 110b, may have an average radial length (RLNAP), and AP 112 comprises an average radial length (RLAP). Along the second major surface 116 of the body 102 of the abrasive article 100, the NAP 110, such as NAP back 110a, may comprise an average radial length (RLNAP2), and AP 112 comprises an average radial length (RLAP2).

In some embodiments, RLAP may be less than RL, such that the AP 112 does not span the entirety of the radial length of the body 102 along the first major surface 114. In some embodiments, RLAP may not be greater than 90% of RL, not greater than 80% of RL, not greater than 70% of RL, not greater than 60% of RL, not greater than 50% of RL, not greater than 40% of RL, not greater than 30% of RL, not greater than 20% of RL, or not greater than 10% of RL. Further, RLAP may be at least 1% of RL, at least 3% of RL, at least 5% of RL, at least 8% of RL, at least 10% of RL, at least 12% of RL, at least 15% of RL, at least 18% of RL, at least 20% of RL, at least 30% of RL, at least 40% of RL, at least 50% of RL, at least 60% of RL, at least 70% of RL, or at least 80% of RL. RLAP may also be in a range between any of these minimum and maximum values, including for example at least 1% of RL to not greater than 90% of RL.

In some embodiments, RLAP2 may also be less than RL, such that AP 112 does not span the entirety of the radial length of the body 102 along the second major surface 116. In some embodiments, RLAP2 may not be greater than 90% of RL, not greater than 80% of RL, not greater than 70% of RL, not greater than 60% of RL, not greater than 50% of RL, not greater than 40% of RL, not greater than 30% of RL, not greater than 20% of RL, or not greater than 10% of RL. Further, RLAP2 may be at least 1% of RL, at least 3% of RL, at least 5% of RL, at least 8% of RL, at least 10% of RL, at least 12% of RL, at least 15% of RL, at least 18% of RL, at least 20% of RL, at least 30% of RL, at least 40% of RL, at least 50% of RL, at least 60% of RL, at least 70% of RL, or at least 80% of RL. RLAP2 may also be in a range between any of these minimum and maximum values, including for example at least 1% of RL to not greater than 90% of RL.

Additionally, RLAP may be different from RLAP2. More specifically, RLAP may be greater than RLAP2. In some embodiments, RLAP is greater than RLAP2 by at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 12%, at least 14%, at least 16%, at least 18%, at least 20%, at least 22%, at least 24%, at least 26%, at least 28%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 100%, at least 105%, or at least 110%. Further, RLAP may be greater than RLAP2 by not greater than 1000%, not greater than 500%, not greater than 200%, or not greater than 100%. RLAP2 may also be in a range between any of these minimum and maximum values, including for example greater than RLAP2 by at least 1% to not greater than 1000% of RLAP2.

Furthermore, in some embodiments, RLNAP may be less than RL, such that NAP 100, more specifically NAP core 110b, may not span the entirety of the radial length of the body 102 along the first major surface 114. In some embodiments, RLNAP may not be greater than 90% of RL, not greater than 80% of RL, not greater than 70% of RL, not greater than 60% of RL, not greater than 50% of RL, not greater than 40% of RL, not greater than 30% of RL, not greater than 20% of RL, or not greater than 10% of RL. Further, RLNAP may be at least 5% of RL, at least 10% of RL, at least 20% of RL, at least 30% of RL, at least 40% of RL, at least 50% of RL, at least 60% of RL, at least 70% of RL, or at least 80% of RL. RLNAP may also be in a range between any of these minimum and maximum values, including for example at least 5% of RL to not greater than 90% of RL. In some embodiments, RLNAP2 may also be less than RL, such that NAP 110, more specifically NAP back 110a, may not span the entirety of the radial length of the body 102 along the second major surface 116. In some embodiments, RLNAP2 may not be greater than 90% of RL, not greater than 80% of RL, not greater than 70% of RL, not greater than 60% of RL, not greater than 50% of RL, not greater than 40% of RL, not greater than 30% of RL, not greater than 20% of RL, or not greater than 10% of RL. Further, RLAP2 may be at least 5% of RL, at least 8% of RL, at least 10% of RL, at least 15% of RL, at least 20% of RL, at least 30% of RL, at least 40% of RL, at least 50% of RL, at least 60% of RL, at least 70% of RL, or at least 80% of RL. RLAP2 may also be in a range between any of these minimum and maximum values, including for example at least 5% of RL to not greater than 90% of RL.

Still referring to FIG. 4, the body 102 of the abrasive article 100 may comprise a first radial length ratio (RL1=RLAP/RLNAP) along the first major surface 114. In some embodiments, RL1 may not be greater than 100. However, in some embodiments, RL1 may not be greater than 90, not greater than 80, not greater than 70, not greater than 60, not greater than 50, not greater than 40, not greater than 30, not greater than 20, not greater than 10, not greater than 5, not greater than 1, not greater than 0.9, not greater than 0.8, not greater than 0.7, not greater than 0.6, not greater than 0.5, not greater than 0.4, not greater than 0.3, not greater than 0.2, or not greater than 0.1. Additionally in some embodiments, RL1 may be at least 0.01, at least 0.05, at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1, at least 1.2, at least 1.5, at least 2, at least 3, at least 4, at least 5, at least6, at least 7, at least 8, at least 9, or at least 10. RL1 may also be in a range between any of these minimum and maximum values, including for example at least 0.01 to not greater than 100.

The body of the abrasive article may comprise a second radial length ratio (RL2=RLAP2/RLNAP2). In some embodiments, RL2 may not be greater than 100.

However, in some embodiments, RL2 may not be greater than 90, not greater than 80, not greater than 70, not greater than 60, not greater than 50, not greater than 40, not greater than 30, not greater than 20, not greater than 10, not greater than 5, not greater than 1, not greater than 0.9, not greater than 0.8, not greater than 0.7, not greater than 0.6, not greater than 0.5, not greater than 0.4, not greater than 0.3, not greater than 0.2, or not greater than 0.1. Additionally in some embodiments, RL2 may be at least 0.01, at least 0.05, at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1, at least 1.2, at least 1.5, at least 2, at least 3, at least 4, at least 5, at least6, at least 7, at least 8, at least 9, or at least 10. RL2 may also be in a range between any of these minimum and maximum values, including for example at least 0.1 to not greater than 90. While abrasive article 100 may comprise a reinforcing member 118 that forms a thin layer over a portion of the NAP 110 and/or the AP 112, it will be appreciated that the average or overall thickness or radial length of the reinforcing member 118 is not included for calculations involving At, Ti, Tp, TAP, RLAP, RLNAP, RL, RLAP2, RLNAP2, RL1, or RL2.

Referring now to FIG. 5, a cross-sectional side view of another embodiment of an abrasive article 200 is shown according to an embodiment of the disclosure. Abrasive article 200 may be substantially similar to abrasive article 100. However, abrasive article 200 comprises at least one of first peripheral comer radius 202 and second peripheral comer radius 204. In some embodiments, abrasive article 200 may comprise both a first peripheral comer radius 202 and a second peripheral corner radius 204. First peripheral corner radius 202 may generally be defined as a radius between the AP 112 at the first major surface 114 and the peripheral side surface 130, while the second periphery comer radius 204 may be defined as the radius between the AP 112 at the second major surface 116 and the peripheral side surface 130.

In some embodiments, the first peripheral corner radius 202 and/or the second peripheral comer radius 204 may comprise a radius that is at least about 5% of the average thickness of the body (Tp) at the peripheral side surface 130, at least about 10%, at least about 15%, at least about 20%, or at least about 25%. The first peripheral corner radius 202 and/or the second peripheral corner radius 204 may comprise a radius that is not greater than 35%, not greater than 30%, not greater than 25%, not greater than 20%, not greater than 15% of the average thickness of the body (Tp) at the peripheral side surface 130. Further, the radius of the first peripheral corner radius 202 and the second peripheral corner radius 204 may comprise any value between these minimum and maximum values, including for example at least about 5% of the average thickness of the body (Tp) at the peripheral side surface 130 to not greater than not greater than 35% of the average thickness of the body (Tp) at the peripheral side surface 130.

Still further, the first peripheral comer radius 202 and the second peripheral corner radius 204 may comprise different values. For example, the first peripheral corner radius 202 may comprise a radius that is greater than the radius of the second peripheral comer radius 204. While each is shown as a rounded surface having a constant radius, first peripheral comer radius 202 and second corner peripheral radius 204 may alternatively comprise chamfered surfaces disposed at an angle to the peripheral side surface 130.

Referring now to FIG. 6, a simplified diagram of functional grinding angles of an abrasive article 100, 200 are shown according to an embodiment of the disclosure. Abrasive articles 100, 200 may include an abrasive-free NAP 110 that does not intersect the periphery side surface 130 of the body 102 with the AP 112 disposed on the periphery of the abrasive article 100 as opposed to throughout the diameter of traditional abrasive wheels. The need to constantly and/or significantly change the grinding angle as the size of the abrasive article 100, 200 decreases may be significantly reduced or even eliminated. Intentional or unintentional increase in the grinding angle therefore may have substantially no effect in gouging a workpiece 300 since the NAP 110 is not exposed to the periphery side surface 130, and since the abrasive-free composition of the NAP 110 does not cut metal. As such, abrasive article 100, 200 may be capable of grinding angles from 0 to 90 degrees. Further, at least in some instances, the range of grinding angle may be less than 0 degrees (e.g., -10 degrees) or greater than 90 degrees (e.g., 110 degrees).

Referring now to FIG. 7, a flowchart of a method 700 of fabricating an abrasive article 100, 200 is shown according to an embodiment of the disclosure. Method 700 may begin at block 702 by forming a precursor body including a non-abrasive portion (NAP) and a green abrasive portion (AP). In some embodiments, the NAP comprises a pre-preg, and forming includes placing the pre-preg into a cavity of a mold. In some embodiments, the NAP may comprise a NAP back 110a and NAP core 110b, each comprising a pre-preg, and forming includes placing the pre-preg NAP back 110a in a mold, and placing the pre-preg NAP core 110b in the mold subsequently. In some embodiments, the pre-preg may be a fully cured polymeric material having a softening point below 150°C. In some embodiments, the NAP preform comprises at least one of bulk molding compound (BMC) and sheet molding compound (SMC). In some embodiments, the NAP may be free of abrasive particles, may comprise chopped strand fibers (CSF), and/or may be formed an uncured mixture of molding compound (MC) and chopped strand fibers (CSF). Furthermore, in some embodiments, method 700 may also comprise placing a shim in the mold and in contact with the NAP pre- preg. More specifically, in some embodiments, the shim may be in contact with the NAP core 110b. The shim may generally comprise a compressible shim, which at least in some embodiments, may allow or provide for better and/or increased compression (an consequently increased density and increased average normalized percent theoretical density) of the green AP as compared to utilizing a non-compressible shim or alternatively, no shim at all. Method 700 may continue at block 704 by forming the precursor body into an abrasive article 100, 200 by selectively applying a different force on the green AP as compared to the NAP for at least a portion of the forming process. In some embodiments, forming may include applying a different force on the green AP as compared to the NAP. In some embodiments, forming the precursor body into an abrasive article 100, 200 includes forming the green AP to have a greater thickness than the NAP and applying force to the green AP prior to applying force to the NAP. In some embodiments, selectively applying a different force includes applying a greater force to the green AP as compared to the NAP in at least one portion of the forming process. In some embodiments, selectively applying a different force includes applying a force to the green AP prior to applying any force to the NAP. In some embodiments, selectively applying a different force includes a force configured to increase the density of the green AP. In some embodiments, the NAP includes a fully densified body prior to the process of forming the precursor body into an abrasive article 100, 200. In some embodiments, forming includes densification of the green AP to form a densified AP. The densified AP may be AP 112. In some embodiments, the result of method 700 may be the AP 112 comprising a density of at least about 90%. Method 700 may also comprise curing the densified AP after densification.

Embodiments of an abrasive article 100, 200 disclosed herein may achieve a measured density and/or an average normalized percent theoretical density greater than that of conventional abrasive articles. In some embodiments, an abrasive article 100, 200 may comprise a measured density of at least about 2.50 grams per cubic centimeter (g/cc), such as at least about 2.51 g/cc, at least about 2.52 g/cc, or at least about 2.53 g/cc, at least about 2.54 g/cc, at least about 2.55 g/cc, at least about 2.56 g/cc, at least about 2.57 g/cc, at least about 2.58 g/cc, or at least about 2.59 g/cc. Additionally, in some embodiments, an abrasive article 100, 200 may comprise a measured density of not greater than 3.0 g/cc, such as not greater than 2.75 g/cc, not greater than 2.65 g/cc, not greater than 2.61 g/cc, not greater than 2.62 g/cc, not greater than 2.61 g/cc, or not greater than 2.60 g/cc. It will be appreciated than abrasive article 100, 200 may also comprise a measured density between any of these minimum and maximum values, including for example, at least 2.51 g/cc to not greater than 2.55 g/cc, at least 2.53 g/cc to not greater than 2.56 g/cc, at least 2.52 g/cc to not greater than 2.54 g/cc, at least 2.57 g/cc to not greater than 2.60 g/cc, or even at least 2.43 g/cc to not greater than 2.52 g/cc.

In some embodiments, an abrasive article 100, 200 may comprise an average percent density of at least about 87.0%, such as at least about 87.1%, at least about 87.2%, at least about 87.3%%, at least about 87.4%, at least about 87.5%, at least about 87.6%, at least about 87.7%, at least about 87.8%, at least about 87.9%, at least about 88.0%, at least about 89%, at least about 90%, at least about 90.1%, at least about 90.2%, at least about 90.3%, at least about 90.4%, at least about 90.5%, at least about 90.6%, at least about 90.7%, at least about 90.8%, at least about 90.9%, at least about 91.0%, at least about 92.0%, at least about 92.1%, at least about 92.2%, at least about 92.3%, at least about 92.4%, at least about 92.5%, or at least about 93.0%. Additionally, in some embodiments, an abrasive article 100, 200 may comprise a percent density of not greater than 95%, not greater than 94%, not greater than 93.5%, not greater than 93.4%, not greater than 93.3%, not greater than 93.2%, not greater than 93.1%, not greater than 93.0%, not greater than 92.9%, not greater than 92.8%, not greater than 92.7%, not greater than 92.6%, not greater than 92.5%, not greater than 92.4%, not greater than 92.3%, not greater than 92.2%, not greater than 92.1%, not greater than 92.0%, not greater than 91.9%, not greater than 91.8%, not greater than 91.7%, not greater than 91.6%, not greater than 91.5%, not greater than 91.4%, not greater than 91.3%, not greater than 91.2%, not greater than 91.1%, not greater than 91.0%, not greater than 90.9%, not greater than 90.8%, not greater than 90.7%, not greater than 90.6%, not greater than 90.5%, not greater than 90.4%, not greater than 90.3%, not greater than 90.2%, not greater than 90.1%, or not greater than 90.0. It will be appreciated than abrasive article 100, 200 may also comprise a percent density between any of these minimum and maximum values, including for example, at least 90.0% to not greater than 91.4%, at least 90.7% to not greater than 91.8%, at least 90.3% to not greater than 91.0%, at least 92.1% to not greater than 93.2%, or even at least 87.1% to not greater than 90.3%.

Furthermore, in some embodiments, an abrasive article 100, 200 may comprise an average normalized percent theoretical density, which may be defined as the average percent density (%) divided by the average thickness (TAVG, measured in millimeters) of the abrasive article 100, 200 at the peripheral side surface (Tp). In some embodiments, an abrasive article 100, 200 may comprise an average normalized percent theoretical density of at least about 16%/mm, such as at least about 17%/mm, at least about 18%/mm, at least about 19%/mm, at least about 20%/mm, at least about 21 %/mm, at least about 22%/mm, at least about 23%/mm, or at least about 24%/mm. Additionally, in some embodiments, an abrasive article 100, 200 may comprise an average normalized percent theoretical density of not greater than 28%/mm, such as not greater than 27%/mm, not greater than 26%/mm, or not greater than 25 %/mm. It will be appreciated than abrasive article 100, 200 may also comprise an average normalized percent theoretical density between any of these minimum and maximum values, including for example, at least about 16%/mm to not greater than 28 %/mm.

Referring now to FIG. 8, a flowchart of a method 800 of conducting a material removal operation is shown according to an embodiment of the disclosure. Method 800 may begin at block 802 by moving an abrasive article 100, 200 relative to a workpiece 300, wherein the abrasive article 100, 200 comprises a body 102 including: a non-abrasive portion (NAP) 110 essentially free of abrasive particles; an abrasive portion (AP) 112 comprising abrasive particles contained in a bond material; and wherein moving the abrasive article 100, 200 relative to the workpiece 300 includes tilting the abrasive article 100, 200 at a functional grinding angle within a range of 0 degrees to 90 degrees. In some embodiments, moving the abrasive article 100, 200 includes changing the functional grinding angle during the material removal operation to a functional grinding angle within a range of at least 0 degrees to 90 degrees. In some embodiments, the workpiece 300 comprises a corner defining an interior angle of less than 180 degrees, and moving the abrasive article 100, 200 includes removing material in the comer at the functional grinding angle. In some embodiments, the comer comprises a comer radius within a range of at least about 5% of an average thickness of the body at a peripheral side surface (Tp) and not greater than 35% of Tp. In some embodiments, moving the abrasive article 100, 200 includes maintaining substantially a same material removal rate over the range of functional grinding angles of at least 0 degrees to 90 degrees.

Examples

Referring to FIG. 9, comparative data of a conventional abrasive articles and embodiments of abrasive articles 100, 200 of the disclosure is shown. A conventional abrasive article having an abrasive-free BMC NAP formed without a shim is compared to embodiments of abrasive articles 100, 200 having an abrasive-free BMC NAP 110 formed with shims of various thickness (1.66 mm, 2.80 mm, 2.3 mm, and 4.5 mm). While these representative thicknesses of shims are used in forming abrasive articles 100, 200 disclosed herein, it will be appreciated that these thicknesses are for example only and not intended to be limiting. As such, any thickness of shim may be used to form abrasive articles 100, 200. The conventional abrasive article formed without a shim achieved a measured density from 2.43g/cc to 2.52g/cc (87.1% density to 90.3% density). Abrasive articles 100, 200 formed using shims achieved measured densities between 2.51g/cc and 2.60g/cc (90.3% density to 93.2% density). Accordingly, abrasive articles 100, 200 formed utilizing shims achieved higher measured densities and percent densities than the conventional abrasive article formed without a shim. As stated, the average normalized percent theoretical density may be defined as the average percent density (%) divided by the average thickness (TAVG, measured in millimeters) of the abrasive article 100, 200 at the peripheral side surface (Tp). The conventional abrasive article achieved an average percent density of 88.7% and had an average thickness at the peripheral side surface of 3.11 mm, thereby achieving an average normalized percent theoretical density of 28.52%/mm (ANPTD=88.7%/3.11mm). The abrasive articles 100, 200 achieved average percent densities of 90.7%, 91.25%, 90.65%, and 92.65% and had average thickness at the peripheral side surface of 4.21 mm, 4.62 mm, 5.29 mm, and 3.84 mm, respectively. Thus, abrasive articles 100, 200, achieved average normalized percent theoretical densities of 21.54%/mm, 19.75%/mm, 17.13%/mm, and 24.12%/mm.

This illustrates that forming abrasive articles 100, 200 using NAP 110 and a shim as disclosed herein allows more consolidation of the coarse mix as measured and/or calculated by the average normalized percent theoretical density of each abrasive article 100, 200. FIG. 7 shows a graph of the comparative data depicted in the chart of FIG. 6 of the conventional abrasive article formed without a shim and embodiments of abrasive articles 100, 200 formed with a shim. FIG. 8 shows a chart of the means, standard deviations, lower 95%, and upper 95% of the percentage of densities achieved in the conventional abrasive article formed without a shim and embodiments of abrasive articles 100, 200 formed with a shim as depicted in the chart of FIG. 6 and the graph of FIG. 7.

In embodiments contemplated by this disclosure, an abrasive article may include one or more of the following items:

Embodiment 1. An abrasive article, comprising: a body including: a non-abrasive portion (NAP) essentially free of abrasive particles; and an abrasive portion (AP) comprising abrasive particles contained in a bond material; wherein the body comprises a radial thickness difference value (At= Tp/Ti) of at least 1.01, and wherein Ti is the average thickness of the body at an inner annular side surface and Tp is the average thickness of the body at a peripheral side surface.

Embodiment 2. An abrasive article comprising: a body including: a non-abrasive portion (NAP) essentially free of abrasive particles; and an abrasive portion (AP) comprising abrasive particles contained in a bond material; wherein the AP comprises an average normalized percent theoretical density of not greater than 28 %/mm.

Embodiment 3. An abrasive article comprising: a body including: a non-abrasive portion (NAP) essentially free of abrasive particles; and an abrasive portion (AP) comprising abrasive particles contained in a bond material; wherein the body comprises a functional grinding angle within a range of 0 degrees to 90 degrees.

Embodiment 4. The abrasive article of any one of Embodiments 2 and 3, wherein the body comprises a radial thickness difference value (At= Tp/Ti) of at least 1.01, wherein Ti is the average thickness of the body at an inner annular side surface and Tp is the average thickness of the body at a peripheral side surface.

Embodiment 5. The abrasive article of any one of Embodiments 1 and 4, wherein the radial thickness difference value (Dΐ= Tp/Ti) is at least 1.02 or at least 1.03 or at least 1.04 or at least 1.05 or at least 1.06 or at least 1.07 or at least 1.08 or at least 1.09 or at least 1.10 or at least 1.11 or at least 1.12 or at least 1.13 or at least 1.14 or at least 1.15 or at least 1.16 or at least 1.17 or at least 1.18 or at least 1.19 or at least 1.20 or at least 1.21 or at least 1.22 or at least 1.23 or at least 1.24 or at least 1.25 or at least 1.26 or at least 1.27 or at least 1.28 or at least 1.29 or at least 1.30.

Embodiment 6. The abrasive article of any one of Embodiments 1 and 4, wherein the radial thickness difference value (At= Tp/Ti) is not greater than 5.00 or not greater than 4.00 or not greater than 3.00 or not greater than 2.00 or not greater than 1.90 or not greater than 1.70 or not greater than 1.50.

Embodiment 7. The abrasive article of any one of Embodiments 1 and 3, wherein the AP comprises an average normalized percent theoretical density of not greater than 28 %/mm.

Embodiment 8. The abrasive article of any one of Embodiments 2 and 7, wherein the AP comprises a density of at least 90%.

Embodiment 9. The abrasive article of any one of Embodiments 1 and 2, wherein the body comprises a functional grinding angle range of at least 0 degrees to 90 degrees.

Embodiment 10. The abrasive article of any one of Embodiments 1, 2 and 3, wherein the body comprises a first peripheral comer radius defined by a portion of the AP at the intersection of a first major surface and a peripheral side surface of not greater than 35% of Tp.

Embodiment 11. The abrasive article of any one of Embodiments 1, 2 and 3, wherein the body comprises a second peripheral corner radius defined by a portion of the AP at the intersection of a second major surface and a peripheral side surface of not greater than 35% of Tp.

Embodiment 12. The abrasive article of any one of Embodiments 1, 2, and 3, wherein the body further comprises: first major surface; a second major surface; a peripheral side surface extending between the first major surface and second major surface; and an inner annular side surface extending between the first major surface and the second major surface.

Embodiment 13. The abrasive article of Embodiment 12, wherein the AP defines a portion of the first major surface and a portion of the second major surface.

Embodiment 14. The abrasive article of Embodiment 12, wherein the AP comprises an average radial length (RLap) at the first major surface, and wherein the RLap is less than an average length (RL) of the body, wherein RLap is not greater than 90% of RL or not greater than 80% or not greater than 70% or not greater than 60% or not greater than 50% or not greater than 40% or not greater than 30% or not greater than 20% or not greater than 10%.

Embodiment 15. The abrasive article of Embodiment 14, wherein RLap is at least 1% of RL or at least 3% or at least 5% or at least 8% or at least 10% or at least 12% or at least 15% or at least 18% or at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80%.

Embodiment 16. The abrasive article of Embodiment 14, wherein the AP comprises an average radial length (RLap2) at the second major surface, and wherein the RLap2 is less than an average length (RL) of the body, wherein RLap2 is not greater than 90% of RL or not greater than 80% or not greater than 70% or not greater than 60% or not greater than 50% or not greater than 40% or not greater than 30% or not greater than 20% or not greater than 10%.

Embodiment 17. The abrasive article of Embodiment 16, wherein RLap2 is at least 1% of RL or at least 3% or at least 5% or at least 8% or at least 10% or at least 12% or at least 15% or at least 18% or at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80%.

Embodiment 18. The abrasive article of Embodiment 16, wherein RLap is different from RLap2.

Embodiment 19. The abrasive article of Embodiment 16, wherein RLap is greater than RLap2.

Embodiment 20. The abrasive article of Embodiment 19, wherein RLap is greater than RLap2 by at least 1% or at least 2% or at least 3% or at least 4% or at least 5% or at least 6% or at least 7% or at least 8% or at least 9% or at least 10% or at least 12% or at least 14% or at least 16% or at least 18% or at least 20% or at least 22% or at least 24% or at least 26% or at least 28% or at least 30% or at least 35% or at least 40% or at least 45% or at least 50% or at least 55% or at least 60% or at least 65% or at least 70% or at least 75% or at least 80% or at least 85% or at least 90% or at least 95% or at least 100% or at least 105% or at least

110%.

Embodiment 21. The abrasive article of Embodiment 19, wherein RLap is greater than RLap2 by not greater than 1000% or not greater than 500% or not greater than 200% or not greater than 100%.

Embodiment 22. The abrasive article of Embodiment 12, wherein the NAP defines a portion of the first major surface and a portion of the second major surface.

Embodiment 23. The abrasive article of Embodiment 22, wherein the NAP defines an average radial length (RLnap) on the first major surface, and wherein the RLnap is less than an average length (RL) of the body, wherein RLnap is not greater than 90% of RL or not greater than 80% or not greater than 70% or not greater than 60% or not greater than 50% or not greater than 40% or not greater than 30% or not greater than 20% or not greater than 10%.

Embodiment 24. The abrasive article of Embodiment 23, wherein RLnap is at least 5% of RL or at least 10% or at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80%.

Embodiment 25. The abrasive article of Embodiment 22, wherein the NAP defines an average radial length (RLnap2) on the second major surface, and wherein the RLnap2 is less than an average length (RL) of the body, wherein RLnap2 is not greater than 90% of RL or not greater than 80% or not greater than 70% or not greater than 60% or not greater than 50% or not greater than 40% or not greater than 30% or not greater than 20% or not greater than 10%.

Embodiment 26. The abrasive article of Embodiment 25, wherein RLnap2 is at least 5% of RL or at least 10% or at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80%.

Embodiment 27. The abrasive article of Embodiment 12, wherein the body comprises a first radial length ratio (RL1 = RLap/RLnap) of not greater than 100, wherein RLnap is the average radial length of the NAP on the first major surface and RLap is the average radial length of the AP on the first major surface, wherein the first radial length ratio is not greater than 90 or not greater than 80 or not greater than 70 or not greater than 60 or not greater than 50 or not greater than 40 or not greater than 30 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 1 or not greater than 0.9 or not greater than 0.8 or not greater than 0.7 or not greater than 0.6 or not greater than 0.5 or not greater than 0.4 or not greater than 0.3 or not greater than 0.2 or not greater than 0.1. Embodiment 28. The abrasive article of Embodiment 27, wherein the first radial length ratio (RL1 = RLap/RLnap) is at least 0.01 or at least 0.05 or at least 0.1 or at least 0.2 or at least 0.3 or at least 0.4 or at least 0.5 or at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9 or at least 1 or at least 1.2 or at least 1.5 or at least 2 or at least 3 or at least 4 or at least 5 or at least 6 or at least 7 or at least 8 or at least 9 or at least 10.

Embodiment 29. The abrasive article of Embodiment 12, wherein the body comprises a second radial length ratio (RL2 = RLap2/RLnap2) of not greater than 100, wherein RLnap2 is the average radial length of the NAP on the second major surface and RLap2 is the average radial length of the AP on the second major surface, wherein the second radial length ratio is not greater than 90 or not greater than 80 or not greater than 70 or not greater than 60 or not greater than 50 or not greater than 40 or not greater than 30 or not greater than 20 or not greater than 10 or not greater than 5 or not greater than 1 or not greater than 0.9 or not greater than 0.8 or not greater than 0.7 or not greater than 0.6 or not greater than 0.5 or not greater than 0.4 or not greater than 0.3 or not greater than 0.2 or not greater than 0.1.

Embodiment 30. The abrasive article of Embodiment 29, wherein the second radial length ratio (RL2 = RLap2/RLnap2) is at least 0.01 or at least 0.05 or at least 0.1 or at least 0.2 or at least 0.3 or at least 0.4 or at least 0.5 or at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9 or at least 1 or at least 1.2 or at least 1.5 or at least 2 or at least 3 or at least 4 or at least 5 or at least 6 or at least 7 or at least 8 or at least 9 or at least 10.

Embodiment 31. The abrasive article of Embodiment 12, wherein the AP defines at least a portion of the peripheral side surface.

Embodiment 32. The abrasive article of Embodiment 12, wherein the AP has a peripheral side surface thickness (Tap) of at least 1% of a total average thickness (t) of the body, or at least 3% or at least 5% or at least 10% or at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90% or at least 95%.

Embodiment 33. The abrasive article of Embodiment 12, wherein the AP has a peripheral side surface thickness (Tap) that extends for the entirety of the total average thickness of the peripheral side surface.

Embodiment 34. The abrasive article of Embodiment 12, wherein the NAP does not intersect the peripheral side surface.

Embodiment 35. The abrasive article of Embodiment 12, wherein the AP does not intersect the inner annular side surface. Embodiment 36. The abrasive article of Embodiment 12, wherein NAP defines the entirety of the inner annular side surface.

Embodiment 37. The abrasive article of Embodiment 12, wherein the AP defines the entirety of the peripheral side surface.

Embodiment 38. The abrasive article of any one of Embodiments 1 and 2, wherein the NAP includes a first NAP portion and a second NAP portion, wherein the first NAP portion has a different size and position compared to the second NAP portion.

Embodiment 39. The abrasive article of any one of Embodiments 1 and 2, wherein the NAP includes a molding compound.

Embodiment 40. The abrasive article of Embodiment 39, wherein the molding compound is at least one of a bulk molding compound (BMC) and a sheet molding compound (SMC).

Embodiment 41. The abrasive article of Embodiment 39, wherein the molding compound comprises at least one of a solvent-free, liquid phenolic resin resole, and a novolac phenolic resin having a melting temperature of less than about 90°C, less than about 80°C, less than about 75°C.

Embodiment 42. The abrasive article of Embodiment 39, wherein the molding compound comprises at least one of hexamethylene tetramine (HMTA) and a novolac phenolic resin having a melting temperature of at least about 70°C, at least about 80°C, at least about 90°C, or at least about 100°C.

Embodiment 43. The abrasive article of Embodiment 39, wherein the molding compound comprises a specific gravity of the MC is at least about 1.4, at least about 1.5, at least about 1.6, at least about 1.7, and not greater than about 1.9, not greater than about 1.8, or not greater than about 1.7.

Embodiment 44. The abrasive article of Embodiment 39, wherein the molding compound comprises a thermoset material.

Embodiment 45. The abrasive article of any one of Embodiments 1 and 2, wherein the NAP has a MOHS scale hardness that is less than about 9, less than about 8, less than about 7, less than about 6, less than about 5, and at least about 1, at least about 2, at least about 3, or at least about 4.

Embodiment 46. The abrasive article of any one of Embodiments 1 and 2, further comprising at least one reinforcing member distinct from the AP and NAP. Embodiment 47. The abrasive article of Embodiment 46, wherein the reinforcing member comprises a glass, fibers, a mat, a woven material, a non-woven material, or a combination thereof.

Embodiment 48. The abrasive article of Embodiment 46, wherein the reinforcing member comprises an average thickness less than an average thickness of the AP or NAP.

Embodiment 49. The abrasive article of Embodiment 46, wherein the reinforcing member is in the form of a layer in contact with at least a portion of the NAP and at least a portion of the AP.

Embodiment 50. The abrasive article of Embodiment 46, wherein the reinforcing member overlies at least a portion of an exterior surface of the body.

Embodiment 51. The abrasive article of any one of Embodiments 1, 2 and 3, wherein the NAP comprises at least one of porosity, chopped strand fibers (CSF), milled fibers, microfibers, organic fillers and inorganic fillers.

Embodiment 52. The abrasive article of any one of Embodiments 1, 2 and 3, wherein the NAP comprises chopped strand fibers (CSF), wherein the NAP comprises at least about 20 vol% CSF for a total volume of the NAP, at least about 25 vol%, at least about 30 vol%, at least about 35 vol%, and not greater than about 40 vol%, not greater than about 35 vol%, not greater than about 30 vol%, not greater than about 25 vol%.

Embodiment 53. A method of fabricating an abrasive article, comprising: (a) forming a precursor body including a non-abrasive portion (NAP) and a green abrasive portion (AP); and (b) forming the precursor body into an abrasive article by selectively applying a different force on the green AP as compared to the NAP for at least a portion of the forming process.

Embodiment 54. The method of Embodiment 53, wherein forming the precursor body into an abrasive article includes forming the green AP to have a greater thickness than the NAP and applying force to the green AP prior to applying force to the NAP.

Embodiment 55. The method of Embodiment 53, wherein selectively applying a different force includes applying a greater force to the green AP as compared to the NAP in at least one portion of the forming process.

Embodiment 56. The method of Embodiment 53, wherein selectively applying a different force includes applying a force to the green AP prior to applying any force to the NAP.

Embodiment 57. The method of Embodiment 53, wherein selectively applying a different force includes a force configured to increase the density of the green AP. Embodiment 58. The method of Embodiment 53, wherein the NAP includes a fully densified body prior to the process of forming the precursor body into an abrasive article.

Embodiment 59. The method of Embodiment 53, wherein forming includes molding the green AP.

Embodiment 60. The method of Embodiment 53, wherein forming includes uniaxial pressing of the precursor body in a mold.

Embodiment 61. The method of Embodiment 53, wherein forming includes applying a shim to a portion of the precursor body prior to selectively applying a different force on the green AP as compared to the NAP.

Embodiment 62. The method of Embodiment 53, wherein forming includes densification of the green AP to form a densified AP.

Embodiment 63. The method of Embodiment 62, further comprising curing the densified AP after densification.

Embodiment 64. The method of Embodiment 53, wherein the NAP comprises a pre- preg, and forming includes placing the pre-preg into a cavity of a mold.

Embodiment 65. The method of Embodiment 64, wherein the pre-preg is a fully cured polymeric material having a softening point below 150°C.

Embodiment 66. The method of Embodiment 64, wherein the NAP preform comprises at least one of bulk molding compound (BMC) and sheet molding compound (SMC).

Embodiment 67. The method of Embodiment 53, wherein the NAP is free of abrasive particles.

Embodiment 68. The method of Embodiment 53, wherein the NAP comprises chopped strand fibers.

Embodiment 69. The method of Embodiment 53, wherein the NAP is formed an uncured mixture of molding compound and chopped strand fibers.

Embodiment 70. A method of conducting a material removal operation comprising: moving an abrasive article relative to a workpiece, wherein the abrasive article comprises a body including: a non-abrasive portion (NAP) essentially free of abrasive particles; an abrasive portion (AP) comprising abrasive particles contained in a bond material; and wherein moving the abrasive article relative to the workpiece includes tilting the abrasive article at a functional grinding angle within a range of 0 degrees to 90 degrees. Embodiment 71. The method of Embodiment 70, wherein moving the abrasive article includes changing the functional grinding angle during the material removal operation to a functional grinding angle within a range of at least 0 degrees to 90 degrees.

Embodiment 72. The method of Embodiment 70, wherein the workpiece comprises a comer defining an interior angle of less than 180 degrees and moving the abrasive article includes removing material in the corner at the functional grinding angle.

Embodiment 73. The method of Embodiment 70, wherein the comer comprises a comer radius within a range of at least about 5% of an average thickness of the body at a peripheral side surface (Tp) and not greater than 35% of Tp.

Embodiment 74. The method of Embodiment 70, wherein moving the abrasive article includes maintaining substantially a same material removal rate over the range of functional grinding angles of at least 0 degrees to 90 degrees.

Embodiment 75. The method of Embodiment 70, wherein the abrasive article has any of the features of Embodiments 1 through 69.

This written description uses examples to disclose the embodiments, including the best mode, and also to enable those of ordinary skill in the art to make and use the invention. The patentable scope is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Note that not all of the activities described above in the general description or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed are not necessarily the order in which they are performed.

In the foregoing specification, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention.

As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

Also, the use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

After reading the specification, skilled artisans will appreciate that certain features are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, references to values stated in ranges include each and every value within that range.