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Title:
INJECTION MOLDS WITH METALLIC GLASS COATING
Document Type and Number:
WIPO Patent Application WO/2020/050851
Kind Code:
A1
Abstract:
The present disclosure is drawn to a kit for manufacturing a polymeric part which includes a polymer feed material and an injection mold. The injection mold can include a metal substrate and a metallic glass coating on the metal substrate, the metallic glass coating defining a mold cavity to receive the polymer feed material and shape the polymer feed material into the polymeric part.

Inventors:
CHEN JIAN-MING (TW)
CHEN CHUN-CHIEH (TW)
CHEN WEN-CHIH (TW)
Application Number:
PCT/US2018/049861
Publication Date:
March 12, 2020
Filing Date:
September 07, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HEWLETT PACKARD DEVELOPMENT CO (US)
International Classes:
B29C33/38; B29C33/56; B29C45/26
Foreign References:
JP2006051702A2006-02-23
US20090236494A12009-09-24
US7938642B22011-05-10
US8657252B22014-02-25
Attorney, Agent or Firm:
COSTALES, Shruti et al. (US)
Download PDF:
Claims:
CLAIMS

What is Claimed is: 1. A kit for manufacturing a polymeric part, comprising:

a polymer feed material; and

an injection mold including a metal substrate and a metallic glass coating on the metal substrate, the metallic glass coating defining a mold cavity to receive the polymer feed material and to shape the polymer feed material into the polymeric part.

2. The kit for manufacturing the polymeric part of claim 1 , wherein the polymer feed material is a resin selected from polycarbonate, acrylonitrile butadiene styrene, polymethyl methacrylate, polypropylene, polystyrene, or a combination thereof.

3. The kit for manufacturing the polymeric part of claim 1 , wherein the metal substrate comprises a steel alloy and the metallic glass coating comprises zirconium.

4. The kit for manufacturing the polymeric part of claim 1 , wherein the metallic glass coating has a lower thermal conductivity than the metal substrate.

5. The kit for manufacturing the polymeric part of claim 1 , wherein a thermal conductivity of the metallic glass coating is from about 1 W/(m K) to about 40 W/(m K).

6. The kit for manufacturing the polymeric part of claim 1 , wherein a Rockwell Hardness value measured on a C scale of the injection mold at the metallic glass coating ranges from about 60 mr to about 80 mr.

7. The kit for manufacturing the polymeric part of claim 1 , wherein an average thickness of the metallic glass coating is from about 400 pm to about 700 pm.

8. The kit for manufacturing the polymeric part of claim 1 , wherein a mold cavity of the injection mold is in a shape of a housing for an electronic device or electronic component.

9. A method of manufacturing a polymeric part comprising:

injection molding a polymer feed material with an injection mold, wherein the injection mold includes a metal substrate and a metallic glass coating on the metal substrate, wherein the metallic glass coating defines a mold cavity to receive the polymer and to shape the polymer into the polymeric part; and

separating the polymeric part from the injection mold.

10. The method of manufacturing the polymeric part of claim 9, further comprising compressing multiple separation portions of the injection mold together during the injection molding.

1 1. The method for manufacturing the polymeric part of claim 9, wherein the polymeric part is a housing for electronics of a laptop, tablet, cellular phone, desktop tower, monitor, keyboard, or mouse.

12. A method of manufacturing an injection mold for forming a polymeric part comprising sputtering a molten metal on a molding portion of an injection mold in an inert gas atmosphere to form a metallic glass coating on the molding portion to form a metallic glass coating that defines a mold cavity.

13. The method of manufacturing the injection mold of claim 12, wherein the metal comprises a steel alloy and wherein the molten metal comprises zirconium or an alloy thereof.

14. The method of manufacturing the injection mold of claim 12, wherein the sputtering occurs at a pressure ranging from about 1 mtorrs to about 5 mtorrs. 15. The method of manufacturing the injection mold of claim 12, wherein the inert gas atmosphere comprises a noble gas, hydrogen gas, nitrogen gas, or a combination thereof.

Description:
INJECTION MOLDS WITH METALLIC GLASS COATING

BACKGROUND

[0001] Polymers are extensively utilized in manufactured products.

Manufactured polymer products can be created by rotational molding, blow molding, compression molding, extrusion molding, thermoforming, or injection molding, for example. The variety of manufactured polymer products is prolific. As the demand for high-quality manufactured polymer products increase, this area continues to expand and evolve to new products and processes.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] FIG. 1 schematically displays an example injection mold in accordance with the present disclosure;

[0003] FIG. 2 is a flow diagram of an example method of manufacturing a polymeric part in accordance with the present disclosure; and

[0004] FIG. 3 is a flow diagram of an example method of manufacturing an injection mold for forming a polymeric part in accordance with the present disclosure.

DETAILED DESCRIPTION

[0005] Injection molding is a manufacturing method for used for mass manufacturing of polymeric parts. During injection molding, a melted polymer feed material can be injected into a mold, allowed to cool, and removed as a polymeric part. In further detail, in some injection molding systems, polymer feed material can be loaded into heated barrel, mixed (such as with a helical shaped screw, for example), and then injected in the cavity of an injection moldy body. The molten polymeric material can be allowed to cool in the injection mold and can solidify to form a polymeric part, where it can then be removed from the mold. In some examples, individual molecular chains of the molten polymer feed material can be stretched when injected in the injection mold and can cool unevenly. The stretching and uneven cooling of molecular chains can shrink the molecular chains of the polymer feed material after it is injected into the injection mold because the molecular chains have a natural tendency to return to a stress- free state. This shrinking of the molecular chains can sometimes result in the formation of thermal residual stress in the formed polymeric part, warping of the polymeric part, or can cause the polymeric part to fail to release properly from the injection mold.

[0006] In accordance with this, the present disclosure is drawn to a kit for manufacturing a polymeric part. The kit can include a polymer feed material and an injection mold. The injection mold can include a metal substrate and a metallic glass coating on the metal substrate, the metallic glass coating defining a mold cavity to receive the polymer feed material and to shape the polymer feed material into the polymeric part. In one example, the polymer feed material can be a resin selected from polycarbonate, acrylonitrile butadiene styrene, polymethyl methacrylate, polypropylene, polystyrene, or a combination thereof. In another example, the injection mold can include a steel alloy and the metallic glass coating can include zirconium. In yet another example, the metallic glass coating can have a lower thermal conductivity than a thermal conductivity of the metal substrate. In a further example, a thermal conductivity of the metallic glass coating can range from about 1 W/(m K) to about 40 W/(m K). In another example, a Rockwell Hardness value measured on a C scale of the injection mold at the metallic glass coating can range from about 60 mr to about 80 mr. In yet another example, an average thickness of the metallic glass coating can be from about 400 pm to about 700 pm. In a further example, a mold cavity of the injection mold can be in a shape of a housing for an electronic device or electronic component.

[0007] A method of manufacturing a polymeric part is also disclosed, and can include injection molding a polymer feed material with an injection mold and separating the polymeric part from the injection mold. The injection mold can include a metal substrate and a metallic glass coating on the metal substrate defining a mold cavity to receive the polymer feed material to shape the polymer feed material into the polymeric part. In one example, the method can further include compressing multiple separation portions of the injection mold together during the injection molding. In another example, the method can be used to manufacture a polymeric part that can be a housing for electronics of a laptop, tablet, cellular phone, desktop tower, monitor, keyboard, or mouse.

[0008] In another example, a method of manufacturing an injection mold for forming a polymeric part is disclosed. In one example, the method can include sputtering a molten metal on a molding portion of an injection mold in an inert gas atmosphere to form a metallic glass coating on the molding portion. The metallic glass coating can define a mold cavity, for example. In one example, the molding portion can be a metal, such as a steel alloy and the molten metal can include zirconium or an alloy thereof. In yet another example, sputtering can occur at a pressure ranging from about 1 mtorrs to about 5 mtorrs. In a further example, an inert gas atmosphere can include a noble gas, hydrogen gas, nitrogen gas, or a combination thereof.

[0009] It is noted that when discussing either the kit for morning a polymeric part, the method for forming a polymer part, or the method for forming an injection mold for a polymer part, such discussions can be considered applicable to one another whether or not they are explicitly discussed in the context of that example. Thus, for example, when discussing the metallic glass coating in the context of one of the kit examples, such disclosure is also relevant to and directly supported in the context of the methods, and vice versa. It is also understood that terms used herein will take on their ordinary meaning in the relevant technical field unless specified otherwise. In some instances, there are terms defined more specifically throughout or included at the end of the present disclosure, and thus, these terms are supplemented as having a meaning described herein.

[0010] In further detail, it is noted that the spatial relationship between two structures can be described herein as one of the structures or coatings being positioned“on” another. This does not infer that the particular structure or coating being described is positioned directly adjacent to the other structure(s) to which it refers, but could have intervening layers or structures therebetween. That being stated, a structure or coating described as being positioned on another structure, can be positioned directly adjacent to or thereon the other structure(s), and thus such a description finds support herein for being positioned directly on the referenced structure as well.

[001 1] Polymer Feed Materials

[0012] Turning now to the kit for manufacturing a polymeric part, in one example, the kit can include a polymer feed material and an injection mold. The term“polymer feed material” refers to polymeric material that can be heated so that it can be flowed into an injection mold for forming an injection molded part in accordance with the present disclosure. Any polymer suitable for injection molding can be used, such as a polycarbonate; a polypropylene; a (meth)acrylic or (meth)acrylate polymer, e.g., polymethyl methacrylate; a styrene, e.g., acrylonitrile butadiene styrene or polystyrene; a copolymer thereof, or a combination thereof. The polymer feed material can be in the form of pellets, granules, particles, powders, etc. , or a combination thereof. In one specific example, the polymer feed material can be acrylonitrile butadiene styrene. In another specific example, the polymer feed material can be polycarbonate. These materials can be heated to temperatures sufficient for injection molding, which can be above the glass transition temperature (Tg) in many instances.

[0013] The polymer feed material can include particulate polymer materials, such as polymer pellets, granules, powders, etc. The size and shape o the polymer feed material can vary based on design choice and is not particularly limited. In some examples, multiple particulate polymer materials can be used.

For example, when the polymer feed material includes more than one polymer, these polymers can have different melting temperatures and rates. These differences can be accounted for by including particulate polymer materials in different shapes and sizes. In some examples, the polymer feed material can have an average particle size ranging from about 50 pm to about 150 pm. In another example, the polymer feed material can have an average particle size ranging from about 80 pm to about 100 pm. In yet another example, the polymer feed material can have an average particle size ranging from about 120pm to about 140 pm, or from about 50 pm to about 70 pm.

[0014] The polymer feed material can further include additives. For example, the polymer feed material can include a colorant such as dyes or pigments, antioxidants, anti-stats, antimicrobials, currants, or any combination thereof. These materials can be used to provide attributes to the manufactured polymeric product. The additives can be added to the polymeric feed material prior to injection into the mold, or can be co-injected into the mold, or can be pre- coated on the mold, etc.

[0015] Injection Molds

[0016] An injection mold can include a metal substrate and a metallic glass coating that can define a mold cavity to receive the polymer feed material and to shape the polymer feed material into the polymeric part. An example injection mold 100 is shown in FIG. 1. As shown, the injection mold can include two portions, portion 100A and portion 100B, that can be adjoined to form an injection mold cavity, shown in part at 106. The injection mold can include a metal substrate 102 with a metallic glass coating 104, and the injection mold cavity can be injected with polymer feed material 1 10 through injection port 108. The polymer feed material can be heated in a barrel and injected using a

reciprocating screw, for example. The cavity can define a shape of the manufactured polymeric part. In one example, the cavity of the injection mold can be shaped as a housing for an electronic device or an electronic component. In a more specific example, the cavity of the injection mold can be shaped as a housing (or portion thereof) for a laptop, tablet, cellular phone, desktop tower, monitor, keyboard, or mouse.

[0017] In further detail, the metal substrate can be a metal or metal alloy, which can include multiple metals alloyed together, or can include one or multiple metals alloyed with relatively small amounts of non-metals, e.g., from about 0 atomic % (at%) to about 10 at% non-metals. To illustrate, even NAK80 steel, which has a low carbon content and is used for injection molds still includes some carbon (about 0.15 at%) and silicon (about 0.3 at%). That being stated, by coating the metal substrate with the metallic glass coatings of the present disclosure, non-metal content of the metal substrate may have less of an impact than when the mold does not include the metallic glass coating. In further detail, the metal substrate can include metal components such as aluminum, brass, bronze, cobalt, copper, iron, magnesium, molybdenum, nickel, silver, tin, tungsten, vanadium, or alloys thereof. If the metal substrate is an alloy with a non-metal, the non-metal component can include carbon, silicon, sulfur, phosphorus, or combinations thereof, for example. In one example, the metal substrate can be a steel alloy, stainless steel alloy, or tool steel alloy (e.g., steels with a carbon content from about 0.5 at% to about 1 .5 at% with iron alloyed with tungsten, chromium, vanadium, and molybdenum). In another example, the metal substrate can be a steel alloy and can include aluminum, copper, manganese, molybdenum, nickel, and can include no more than about 8 at% combined carbon and silicon.

[0018] The metallic glass coating can be an amorphous coating, e.g., lacking a crystalline structure in its solid state, and can include a metal or metal alloy. For example, the metallic glass coating can include actinium, aluminum, bohrium, cadmium, chromium, cobalt, copernicium, copper, darmstadtium, dubnium, gold, hafnium, hassium, iridium, iron, lanthanum, manganese, magnesium, meitnerium, mercury, molybdenum, nickel, niobium, osmium, palladium, platinum, rhenium, rhodium, roentgenium, ruthenium, scandium, seaborgium, silver, tantalum, technetium, titanium, tungsten, vanadium, yttrium, zinc, zirconium, and alloys thereof. In one example, the metal glass coating can be zirconium or a zirconium alloy.

[0019] The thickness of the metallic glass coating on the metal substrate can from about 100 pm to about 1 mm in average thickness. In some examples, the metallic glass coating can be present on the metal substrate at a thickness ranging from about 400 pm to about 700 pm, from about 100 pm to about 600 pm, from about 500 to about 600 pm, or from about 300 pm to about 800 pm.

[0020] Mold temperatures can also be controlled to provide acceptable injection molded part integrity. In some instances, injection temperatures (or melt temperatures) can be kept low to not degrade the polymer during injection, and mold temperatures traditionally may have been kept higher to extend the cooling time of the polymer part. However, in accordance with one example of the present disclosure, by utilizing the metallic glass coatings of the present disclosure, such as when the thermal conductivity for the metallic glass coating is lower than the thermal conductivity of the metal substrate, cooling the lower thermal conductivity of the metallic glass coating can provide for slower cooling due to the nature of the material.

[0021] As used herein,“thermal conductivity” refers to a material’s ability to transfer heat, e.g., absorb, retain, and/or dissipate heat. Heat transfer can occur at a lower rate across materials of low thermal conductivity than across materials of high thermal conductivity, and can occur at different rates in objects that contain sections composed of different materials. Heat transfer can occur by conduction, convection, and/or radiation. Thermal conductivity can be

characterized herein using watts per kelvin per meter, or W/(m K), which are the units of the International System of Units (SI). A Thermal Conductivity Analyzer can be used to measure thermal conductance. The heat transfer rate can be calculated as shown below in Formula (I), where Q = energy, t = time, d = thickness, K = thermal conductivity (W/m °K), A = cross-sectional area, and T H -T L = temperature difference from a high temperature (T H ) to a low temperature (T L ).

Heat transfer rate dQ/dt = K. A * (TH-TL)/d Formula (I)

[0022] The thermal conductivity of the metallic glass coating can be less than a thermal conductivity of the metal substrate. Without being limited by theory, it is believed that the lower thermal conductivity of the metallic glass coating can reduce the cooling rate (slow the rate of cooling) of a polymer feed material injected therein. The reduced cooling rate can reduce stresses caused by rapid cooling of the polymer feed material, can reduce the occurrence of molecular chain shrinkage, and can result in a manufactured polymeric part that can have less warping, for example. In one example, a thermal conductivity of the metallic glass coating can range from about 1 W/(m K) to about 40 W/(m K). In other examples, a thermal conductivity of the metallic glass coating can range from about 15 W/(m K) to about 30 W/(m K), from about 5 W/(m K) to about 35 W/(m K), from about 5 W/(m K) to about 25 W/(m K), or from about 10 W/(m K) to about 35 W/(m K), measured at 25 °C. The thermal conductivity of steel with about 1 at% carbon is about 43 W/(m K), and the thermal conductivity for iron is about 80 W/(m K) and for cast iron is about 58 W/(m K). On the other hand, the thermal conductivity of stainless steel is about 16 W/(m K). Thus, even in the iron alloys, the thermal conductivities vary fairly widely. The thermal conductivities for bronze and brass are both at about 1 10 W/(m K), and for chromium, the thermal conductivity is about 94 W/(m K), whereas the thermal conductivity of titanium is only about 22 W/(m K). Thus, when selecting a metallic glass coating, in one example, the thermal conductivity of the metal substrate can be considered and then metallic glass coating having a lower thermal conductivity can be applied.

[0023] The metallic glass coating can also prolong a useable life of the injection mold. Metallic glass, in general, can lack defects because it is non- crystalline in structure, can exhibit a high hardness values, can be corrosion resistant, can be wear resistant, and can exhibit fatigue strength. These properties of metallic glass can increase a useable life of an injection mold by reducing mold wear that can occur on a metal substrate mold that lacks the metallic glass coating.

[0024] In one example, the metallic glass coating can have a Rockwell Hardness value greater than a Rockwell Hardness value of the metal substrate. As used herein, a“Rockwell Hardness value” refers to the resistance of a material to resist penetration at its surface by another material and is related to wear resistance and strength. The higher a Rockwell Hardness value the higher the strength of the material. The Rockwell Hardness value can be determined with an indenter. In one example, the indenter can apply a test force (primary test force F0} F0 and total test force {F0+F1 ) to a surface of the test material, twice. Under the test force, the indenter can be pressed into the a surface of the test material for a certain period of time. Then, the main test force F1 can be removed, and the indentation depth can be measured with the initial test force F0 maintained. A difference between the indentation depth at the total test force and the indentation depth at the initial test force can characterize the hardness. The larger the residual indentation depth value, the lower the hardness value and vice versa. In one example, the Rockwell Hardness value can be determined using ASTM E 18 Standard Test Methods for Rockwell Hardness and Rockwell Superficial Hardness of Metallic Materials. [0025] In one example, a steel alloy metal substrate can have a Rockwell Hardness value measured on a C scale ranging from about 40 mr to about 60 mr whereas a zirconium metallic glass coating on the steel alloy metal substrate can have a Rockwell Hardness value on a C scale of about 70 mr. In one example, a Rockwell Hardness value measured on a C scale of the injection mold at the metallic glass coating can range from about 60 mr to about 80 mr. In other examples, a Rockwell Hardness value measured on a C scale of the injection mold at the metallic glass coating can range from about 65 mr to about 75 mr, from about 60 mr to about 70 mr, or from about 70 mr to about 80 mr.

[0026] The metallic glass coating can be coated at a cavity of the injection mold or can be coated at the cavity of the injection mold. In other examples, some not only is the cavity coated, but the entire parting line(s) of the injection mold can also be coated. The parting line can be defined as the area of a surface that defines a portion of the cavity where multiple portions of an injection mold are brought together to contact one another. For example, as shown in FIG. 1 , the parting line of portion 100A can be defined as a surface of metallic glass coting that surrounds and defines an outer shape of the cavity shown at 106.

[0027] In some examples, the injection mold can further include features that benefit the manufacturing process. For example, the injection mold can include an injection port (shown at 108 in FIG. 1 ), runner, slug, air vents, cooling lines, alignment pin holes, alignment pins, ejector pins, separation slots, or any combinations thereof. In one example, the injection mold can include a slug. A slug can catch any slightly solidified polymer feed material that is initially injected into the injection mold. In some examples, the injection mold can include an air vent to allow air within a cavity of the injection mold to exit the injection mold as melted polymer feed material is injected into the injection mold. In some examples, the air vent can be very shallow. For example, the air vent can have a depth ranging from about 0.3 mm to about 0.6 mm. In yet other examples, the air vent can have a depth ranging from about 0.4 mm to about 0.5 mm, from about 0.3 mm to about 0.5 mm, or from about 0.4 mm to about 0.6 mm. This depth can allow for air to pass through the air vent but can be too small for the melted polymer feed material to enter the air vent. The quantity and location of air vents can vary based on the size and shape of the injection mold. [0028] Methods of Manufacturing a Polymeric Parts

[0029] In another example, as illustrated in FIG. 2, is a method 200 of manufacturing a polymeric part can include: injection molding 202 a polymer feed material with an injection mold. The injection mold can include a metal substrate and a metallic glass coating that can define a mold cavity to receive the polymer feed material and to shape the polymer feed material into the polymeric part. The method can also include separating 204 the polymeric part from the injection mold. In some examples, the injection mold can include ejector pins that can be used to separate the polymeric part from the injection mold. In yet other examples, the polymeric part can be manually separated from the injection mold. The polymeric feed material and injection mold utilized in the method can be as described above.

[0030] In some examples, the method can include additional steps. In one example, the method can include compressing multiple separation portions of the injection mold together during injection molding. This can occur in instances where the injection mold includes a multiple portions, such as shown in FIG. 1 at 100A and 100B, which may not be completely abutting prior to injection of a polymer feed material in a cavity of an injection mold. The presence of a gap can allow for additional airflow as the polymer feed material is injected in a cavity of an injection mold, which can thereby allow for a further reduction in the cooling rate of the polymer feed material. In other examples, the method can include circulating a coolant through or around the injection mold after injection molding of a polymer feed material, but prior to separating the polymeric part from the injection mold.

[0031] In some examples, the method can be used to manufacturing a polymeric part that can be a housing for an electronic device or an electronic component. In other examples, the manufactured polymeric part can be a housing for electronics of a laptop, tablet, cellular phone, desktop tower, monitor, keyboard, or mouse. [0032] Methods of Manufacturing an Injection Molds

[0033] In another example, as illustrated in FIG. 3, is a method for 300 manufacturing an injection mold for forming a polymeric part can include sputtering 302 a molten metal on a molding portion of an injection mold in an inert gas atmosphere to form a metallic glass coating on the molding portion to form a metallic glass coating that defines a mold cavity. The molding portion can be located on a metal substrate as described above. The“molding portion” of the injection mold can provide a base support for forming the plastic part, and may include an opening or pre-cavity for example, which is approximately the desired inverse shape for the plastic part, e.g., approximating cavity shape minus the thickness of the metallic glass coating to be applied. The molten metal can be a metal or a metal and non-metal as described above with respect to the metallic glass coating. The molten metal can contact the molding portion of the injection mold and solidify in an amorphous state on the surface thereof forming a metallic glass coating.

[0034] In some examples, the sputtering can occur via physical vapor deposition. In one example, the physical vapor deposition can deposit a thin film on the substrate of the injection mold. The sputtering can occur at a pressure that can range from about 1 mtorrs to about 5 mtorrs, from about 2 mtorrs to about 4 mtorrs, or from about 3 mtorrs to about 5 mtorrs. In some examples, the sputtering can occur at an elevated temperature. For example, the sputtering can occur at a temperature ranging from about 100 °C to about 500 °C, from about 200 °C to about 400 °C, from about 250 °C to about 500 °C.

[0035] The inert gas atmosphere can interact with the sputtered molten metal ions and can cause the molten metal ions to fly towards the injection mold in a straight line and can cause the molten metal ions to energetically impact the injection mold. The molten metal ions can then form a film on the injection mold. Examples of the inert gas atmosphere can include noble gases, e.g., helium, neon, argon, xenon, krypton, etc. , hydrogen, nitrogen, or combinations thereof. In one example, the inert gas atmosphere can be argon gas, nitrogen gas, or a combination of argon gas and nitrogen gas. [0036] Definitions

[0037] It is noted that, as used in this specification and the appended claims, the singular forms”a,”“an,” and“the” include plural referents unless the context clearly dictates otherwise.

[0038] "Average” with respect to properties of a polymer feed material refers to a number average unless otherwise specified. Accordingly,“average particle size” refers to a number average particle size. Additionally,“particle size” refers to the diameter of spherical particles, or to the longest dimension of non- spherical particles.

[0039] As used herein, the term“about” is used to provide flexibility to a numerical range endpoint by providing that a given value may be“a little above” or“a little below” the endpoint. The degree of flexibility of this term can be dictated by the particular variable and determined based on the associated description herein.

[0040] As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary.

[0041] Concentrations, amounts, and other numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range but also to include individual numerical values or sub- ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. As an illustration, a numerical range of“about 1 wt% to about 5 wt%” should be interpreted to include not only the explicitly recited values of about 1 wt% to about 5 wt% but also include individual values and sub-ranges within the indicated range. Thus, included in this numerical range are individual values such as 2, 3.5, and 4 and sub-ranges such as from 1-3, from 2-4, and from 3-5, etc. This same principle applies to ranges reciting only one numerical value. Furthermore, such an interpretation should apply regardless of the breadth of the range or the characteristics being described

EXAMPLES

[0042] The following illustrates examples of the present disclosure.

However, it is to be understood that the following is only illustrative of the application of the principles of the present disclosure. Numerous modifications and alternative kits, compositions, methods, and systems may be devised without departing from the spirit and scope of the present disclosure. The appended claims are intended to cover such modifications and arrangements.

Example 1 - Method of Manufacturing an Injection Mold

[0043] An injection mold is manufactured by melting steel bars in the shape of a mold base. The steel is a steel alloy with less than about 1 at% carbon with a thermal conductivity of about 43 W/(m K). The mold base is mounted on a milling machine, shaved to the desired dimension, drilled at locations for guide pins and bushings, and ground to smooth surfaces of the mold base. A computer- guided tooling machine then shapes a molding portion of the mold to form a features, such as an opening or pre-cavity, which is approximately the desired inverse shape for the plastic part, e.g., approximating cavity shape minus the thickness of the metallic glass coating to be applied. A computer-guided fine tooling machine can further shape the pre-cavity of the mold to incorporate fine details, boring holes can also be drilled for cooling lines, and/or other mold features or details can also be added, as may be appropriate.

[0044] Physical vapor deposition is then utilized to deposit a metallic glass coating on the molding portion of the metal substrate by positioning the molding portion in an inert gas environment of nitrogen and argon gas. Zirconium is then heated to a temperature ranging from about 250°C to about 300°C and sputter deposited on the molding portion surface at a pressure of about 3 mtorrs. The argon and nitrogen gas environment allow the melted zirconium to travel in a straight line to energetically impact the cavity surface of the mold. The melted zirconium then cools on the cavity surface of the mold and forms an amorphous metallic glass coating on the cavity. The metallic glass coating is applied to have a thickness of about 500 pm. Zirconium has a thermal conductivity of about 23 W/(m K).

Example 2 - Method of Manufacturing a Polymeric Part

[0045] A polycarbonate polymeric feed material in the shape of 1 mm pellets is loaded in a barrel of an injection molding system, and then the polymer feed material is fed through the interior of the injection system by a reciprocating screw. The polymer feed material is heated to an injection temperature of about 300 °C. As the polymeric feed material melts, heat and friction that can be created by the reciprocating screw and by heating bands allows the molten polymer feed material to be injected into a cavity of the injection mold prepared in accordance with Example 1. The molten polymeric material is allowed to cool in the injection mold, therein forming the polymeric part. Cooling rates are estimated to be about 15% slower than cooling rates using the same metal substrate as the mold without the metallic glass coating applied thereto. The solidified polymeric part is then separated from the injection mold. The amorphous metallic glass coating thus reduces the rapid cooling of the polymeric feed material and as a result, reduces the incidence of the polymeric molecular chain shrinkage.

[0046] What has been described and illustrated herein is an example of the disclosure along with some of its variations. The terms, descriptions, and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the spirit and scope of the disclosure, which is intended to be defined by the following claims - and their equivalents - in which all terms are meant in their broadest reasonable sense unless otherwise indicated.