Control system and method for additive manufacturing The present invention relates to a quality control method of a stock of a base material for the additive manufacture of components, preferably for a plurality of additive manufac ^¬ turing jobs. Further, the present invention relates to a control system for handling and assuring the quality of a stock of base material and a facility comprising the control sys ^¬ tem. Still further, the present invention relates to a com ^¬ puter readable medium.

Powder bed manufacturing methods such as selective laser melting or selective laser sintering are relatively well known methods for fabricating, prototyping or manufacturing parts or components from powder material, for instance. Con ^¬ ventional apparatuses or setups for such methods usually com ^¬ prise a manufacturing or build platform on which the compo- nent is built layer-by-layer after the feeding of a layer of base material which may then be melted, e.g. by the energy of a laser beam and subsequently solidified. The layer thickness is determined by a wiper that moves, e.g. automatically, over the powder bed and removes excess material. Typical layer thicknesses amount to 20 ym or 40 ym. During the manufacture, said laser beam scans over the surface and melts the powder on selected areas which may be predetermined by a CAD-file according to the geometry of the component to be manufac ^¬ tured .

In the field of additive manufacturing, with respect to both, research and mass production, there is currently little known about the effects of using recycled or reused powder on the final quality of the as-manufactured component or part. Thus, there is the need for a system which allows for a reliable tracking and/or management of a base material stock, prefera ^¬ bly a powder stock. To this effect, the present invention aims preferably at powder-bed-based manufacturing processes. Actually, in the state-of-the-art additive manufacture it has to be coped with the huge amounts of various types of base materials which are usually present in a plurality of recy- cling states. This makes it generally very difficult to track the quality and manage the movement of portions of base mate ^¬ rial, which may be present in numerous containers, manufac ^¬ turing systems or powder buckets of the system. The mentioned "recycling" shall particularly pertain to base material which is or is to be used again for a manufacturing job or the buildup of the component once said material has already been present in a manufacturing space or build area or exposed to the respective manufacturing conditions such as exposure to a laser or electron beam for solidification of the base material.

Currently the effects of the mentioned manufacturing condi ^¬ tions on the quality or performance of the base material, such as the powder, are not very well defined and or under ^¬ stood, as the quality of e.g. the powder depends on various different aspects, such as e.g. laser parameters, particular ^¬ ly the exposure of the base material to heat in the build ar ^¬ ea. Therefore, there is the need to provide a powder control system and a quality control method. Particularly, it is an object of the present invention to provide means to enable or improve the quality assurance and/or handling the base mate ^¬ rial of during additive manufacturing research and/or industry .

The mentioned object is achieved by the subject-matters of the independent claims. Advantageous embodiments are subject- matter of the dependent claims. The mentioned "components" may be any ceramic or metallic components or plastic components. Preferably, the components may pertain to components of a turbine, such as a gas tur ^¬ bine . The term "additive" in the context of manufacturing shall particularly denote a layer-wise, generative and/or bottom-up manufacturing process. The additive manufacturing as de- scribed herein may be or relate to rapid prototyping.

An aspect of the present invention relates to a control sys ^¬ tem for assuring quality and/or handling a stock or inventory of the base material for an additive manufacture of a compo- nent, wherein the control system comprises a plurality of containers for retaining the base material. The control sys ^¬ tem is further configured to track or trail the base material or the location of the base material and, preferably, its quality during a plurality of manufacturing jobs or buildup processes of the components in that the stock is or can be subdivided into a plurality of batches of the respective base material, wherein each batch comprises base material of the same quality. Preferably, the batch also holds information about the type of base material, e.g. the manufacturing line or material system. Particularly, said tracking is advantageous in order to keep a user or operator of the control sys ^¬ tem informed of the powder quality present in a corresponding manufacturing system over a large number of manufacturing j obs .

The term "batch" preferably relates to a virtual and/or phys ^¬ ical indexing but pertaining to the physical amount of mate ^¬ rial . In an embodiment, the base material is a powdery or granular material for the respective component.

In an embodiment, the control system is configured to provide information about a quality and/or a disposability, such as a quantity and location of the base material.

The control system comprises a processing system being connected to an operator interface or the like for receiving and processing instruction from an operator of control system and to display information to said operator. In this way, the control system and a corresponding quality control method of the stock may easily be adapted to the operator' s needs and can be administered by the operator.

A further aspect of the present invention relates to a facil ^¬ ity for additively manufacturing of a component. The facili ^¬ ty, preferably being configured for additively building up a plurality of user-defined components, comprises the control system as described. The facility further comprises a manu ^¬ facturing system for the additive manufacture of the compo ^¬ nent (s) out of the base material, wherein the manufacturing system may comprises a conveyor system being configured to convey base material in and out of the build area and, pref ^¬ erably also between the different containers and the manufac ^¬ turing system. The conveyor system may in turn comprise wipers or pistons in order to be able to convey the base materi ^¬ al expediently. Additionally or alternatively, the conveyor system may comprise means for conveying base material by air blasts or pressurized air.

In an embodiment, the manufacturing system comprises a plu ^¬ rality of build areas, e.g. for a plurality of different ma- terials to be manufactured in a separate manufacturing line, setup or sub-system, each.

The facility can be an industrial manufacturing line for the additive manufacture of components of a plurality of differ- ent materials.

A further aspect of the present invention relates to a quali ^¬ ty control method of a stock of the base material for the ad ^¬ ditive manufacture of components comprising selecting a batch of the base material out of a plurality of indexable or in ^¬ dexed batches of the stock, wherein base material assigned to or indexed with the same batch index is indicative to the quality of the respective base material. The selection is preferably made by the user or operator of the method and/or the control system.

By means of the batch indices or batch indexing, a classifi- cation of base material of the stock may advantageously be provided .

The method further comprises loading or filling of a quantity of base material of the selected batch into the manufacturing system.

In an embodiment, said quantity is pre-defined by the user or the operator. The method further comprises additively manufacturing or building up the component from the base material, wherein the base material of the selected batch is exposed to manufactur ^¬ ing conditions, such as the heat of a solidifying laser or electron beam in the build area. Most preferably, the expo- sure to the manufacturing conditions pertains to the exposure to heat in the build said exposure may result in a sticking or conglomeration of at least parts of the base ma ^¬ terial. Thereby, the mentioned base material is of course rendered unusable and has to be sieved or filtered before it can be recycled or re-used. Powdered base material which hasn't been hit e.g. by the laser beam and filtered prefera ^¬ bly still provides its nominal properties, e.g. in terms of powder fraction and/or particle size. Additionally or alternatively, the heat of the corresponding solidifying unit, such as the laser, may cause deterioration of the powder material or oxidation which in turn affects the suitability of said base material for further manufacturing jobs in an adverse way.

In an embodiment, the base material remaining from the addi ^¬ tive manufacture in the build area is sieved or filtered af ^¬ ter the corresponding additive manufacture. The method further comprises updating the batch index of the base material remaining from or after the additive manufac ^¬ ture in the build area according to the exposure to the manu- facturing conditions. Said updating preferably relates to an increase of the batch index by one increment.

Thereby, means are provided, by which the user or operator of the control system or as the case may be the described method is able to effectively track the desired base material por ^¬ tion and its quality preferably during the whole operation of the described manufacturing system and/or facility.

By the present invention, quality control, management and/or handling of base material may be facilitated by means of the "batch-identification", as described. The batches are preferably non-physical entities to which all of the powder of the stock belongs regardless of the physical container it is ac ^¬ tually retained in. The method or handling system as de- scribed is particularly also useful in a software environ ^¬ ment, wherein the batches can be used as a collective area for all of the individual base material portions of the same condition, therefore allowing an operator for much a quicker overview of the current base material situation as compared to the current practice, wherein each container has to be physically checked in the respective working area in a com ^¬ plicated way, before the next manufacturing job can be ini ^¬ tialized. The control system is configured to track the base material and its quality by means of the batch index of the base mate ^¬ rial during the plurality of manufacturing jobs.

In an embodiment, the base material and its quality are tracked in that the stock of the base material is retained in different containers which are numbered and assigned to or indexed with a batch index each. Nevertheless, it may readily be possible that base material which has been assigned to a single batch is contained in different containers, such that the batch, which is preferably not a physical single contain ^¬ er, consists of the base material in the different contain ^¬ ers .

In an embodiment, the date, the respective container was filled in the current amount of base material in that con ^¬ tainer or the container weight is registered by the control system. Thereby, the tracking of the powder material within the whole facility or manufacturing system may be facilitat ^¬ ed .

In an embodiment, the containers are indicated with a con ^¬ tainer number, and a type of base material being contained in the respective container. Accordingly, it may further be indicated if the respective container is a fresh one or a con ^¬ tainer which has already been opened or begun.

The quantity of powder to be loaded into the manufacturing system is entered manually into the control system by the us ^¬ er or operator.

The quantity of the base material remaining from or after the additive manufacture or the recent manufacturing job is auto- matically calculated by the control system, e.g. based on a position of a feed piston of a manufacturing system which is provided in the build area in order to provide the base mate ^¬ rial to the actual build area or level. In an embodiment, prior to the loading, a filling status of the manufacturing system, or as the case may be, the different containers, is checked by the control system. Said check may further comprise the control of the amount of base mate ^¬ rial actually present in the build area, the location of the mentioned piston, thus filling status of the build area and to whether a correct a wrong batch and/or container has been selected by the operator. In an embodiment, the control system is configured such that the control system informs the user or operator or warns him when a filling status of a container, preferably a fresh container with a batch index of "00", is below an alarm level or a false or non-disposable batch or batch index has been se ^¬ lected by the user. This particular embodiment can advanta ^¬ geously improve quality control and handling of the base ma ^¬ terial of the whole manufacturing system or facility and im ^¬ prove the disposability of the base material in general.

In an embodiment the control system is configured to propose a batch of a base material for a subsequent manufacturing job to the operator. Thereby, the operator may be supported in his decision (s) concerning the proximate manufacturing job.

In an embodiment, the base material remaining from the addi ^¬ tive manufacture is either removed from the manufacturing system and recycled, preferably also filtered, or left inside the build area for a subsequent manufacturing job.

In an embodiment, the method is performed such that, when the base material remaining from the additive manufacture shall be removed, e.g. according to an operator decision, said base material is conveyed to a container corresponding to the up- dated batch index of that base material. Said container may, thereby, be a container which already comprises base material of the same batch (index) .

A further aspect of the present invention relates to a, pref- erably non-transitory, computer-readable medium comprising executable instructions being suitable to cause the pro ^¬ cessing system and/or the described control system to execute the following steps:

assigning batch indices to a plurality of batches of a base material for an additive manufacture of a component based on an operator selection,

updating a batch index of the selected base material once the base material has been exposed to the respective man- ufacturing conditions, thereby tracking the base material and its quality by means of the batch indices.

Advantages relating to the described method and/or the de- scribed computer readable medium may as well pertain to the control system and/or the facility as described.

Further features, expediencies and advantageous refinements become apparent from the following description of the exem- plary embodiment in connection with the Figures.

Figure 1 shows a schematic of a manufacturing system.

Figure 2 shows a schematic of a facility according to the

present invention.

Like elements, elements of the same kind and identically act ^¬ ing elements may be provided with the same reference numerals in the figures.

Figure 1 shows a schematic of a manufacturing system 100. The manufacturing system 100 is preferably a system or device for additively manufacturing of a component 1 by means of a pow ^¬ der bed manufacturing process, such as selective laser melt- ing. Alternatively, the manufacturing process may be or com ^¬ prise selective laser sintering and/or electron beam melting. Accordingly, in the manufacturing system 100, the component 1 is preferably manufactured or build up layerwise. Particular ^¬ ly Selective Laser Melting (SLM) is a preferred powder-bed additive manufacturing process by which a high power laser can be used to build up a 3D part layer-by-layer for research and/or industrial applications.

The component 1 may be any user-defined or pre-defined plas- tic ceramic but preferably metallic component which is to be additively manufactured in the manufacturing system 100. Preferably, the component 1 is a turbine component, e.g. a part to be applied in gas turbines and required to withstand large temperatures. The component 1 is only depicted partly as the component shall be shown during its additive manufac- ture or buildup.

The manufacturing system 100 comprises a build platform 3. The build platform 3 is movable by means of a drive compris ^¬ ing e.g. a feed piston 5. The manufacturing system 100 fur- ther comprises base material 2 out of which the component is to be manufactured. Preferably, the base material 2 is a met ^¬ al powder. The base material 2 is preferably mainly retained in base material supply 9. The supply 9 comprises a further piston 6 for providing the base material 2. The further pis- ton 6 is preferably displaceable vertically in order to allow for further base material to be delivered into the build area 50.

The manufacturing system 100 further comprises a wiper, scraper or deposition unit 4 by means of which base material can be moved from the supply 9 into a build area 50 of the manufacturing system 100 (e.g. from right to left) . Access powder is then preferably directly moved into a discharge or overflow container 15 of the manufacturing system 100. The overflow container 15 is expediently arranged at a side of the build area 50 which is opposed from the location of the supply 9.

Once a layer of base material 2 has been spread in the build area, e.g. on top of the build platform 3, it is expediently melted and subsequently solidified, preferably by means of a beam of a laser 8, which may be scanned over a surface of the component 1. Later, the feed piston 5 is preferably lowered by a distance according to the thickness of the as-solidified layer of the component 1, e.g. by 40μιη.

At the end of a respective build job, any base material 2 in the manufacturing system 100 and around the component 1, ei- ther in the overflow container 15 or still on top of the feed piston 5 can be sucked out, e.g. with a specialized vacuum equipment (not explicitly indicated) and preferably filtered or sieved, e.g. by a filter (not indicated) . Said sieving is particularly important as - due to the exposure to the heat of a laser or electron beam of the additive manufacturing system - the base material may be partly solidified to clus ^¬ ters. By the sealing of filtering, said clusters - which may result from weld spattering - may be separated and the rest of the base material and its original state may be recycled.

Thereby, the quality of the expensive base material 2 can ad ^¬ vantageously be registered and assured, which is particularly desirable in case of high-performance materials as in the case of gas turbine components. Moreover, the user or opera ^¬ tor is given the possibility to track the quality as well as disposability of a plurality of portions or subquantities of the base material stock. Particularly, the operator or manufacturer of the component 1 may e.g. retroactively track the quality of the powder in that the system holds and/or stores information about the source of base material or the batch index thereof even after the component has already been finished.

Selective laser melting is still a relatively juvenile tech ^¬ nology and so the effects on the powder due to going through the process are still not fully understood. To this effect a system which allows for controlling quality as well as han- dling of the base material requires not only the ability to have an inventory view of what base material 2 is available but also e.g. what state the powder is in and how many times it has e.g. been exposed the process conditions of manufac ^¬ turing. Further, the base material may deteriorate or lose performance over time.

According to the present invention, a batch or bucket indexing is provided by means of which base material of the same qualitative state, i.e. comprising the same a batch index, can be tracked, preferably, over the whole lifetime of the base material 2 and/or the manufacturing system 100. The mentioned usage of batch indices - as will be described below mainly in conjunction with Figure 2 - provide for a significant improvement over a mere cycling index, for in ^¬ stance. In other words, the batch index allows for the indi ^¬ cation and tracking of all of those physical properties which are relevant for the performance of the component to be manu ^¬ factured. Therefore, pertinent testing processes, e.g. in ^¬ cluding elemental analysis of the respective powder portion may be conducted on occasion. The sole tracking of a cycle number, wherein e.g. it is only tracked how often a powder portion is moved from one container to the other is not necessarily relevant as this portion may not have been subjected to the manufacturing conditions and in this way may haven't deteriorated significantly.

Important parameters which may significantly influence the quality of a specific quantity or portion of base material 2 is the time the respective portion has been exposed to a ra ^¬ diation source or electron beam for solidification. In this way also the power of that radiation source may be crucial. Thus, the most crucial impact on the performance of the base material once it has been exposed to the manufacturing condi ^¬ tions is e.g. the heat of the laser which usually dominates oxidation behavior. The oxygen content of the powder and/or the as-manufactured component may later on be checked in a respective laboratory analysis by means of the pertinent methods. This is particularly expedient after a specific por ^¬ tion of base material or batch index has e.g. been exposed to the heat of the laser for 15 to 20 times.

Still further, the particle fraction or particle size distri ^¬ bution of the powder particles, may vary, particularly the powder particles may cluster and/or conglomerate caused by weld spattering. By the above-mentioned sieving process, which is most preferably carried out every time the respec ^¬ tive base material portion has been exposed to the laser heat, the clusters can be separated and the still usable share of that base material may be recycled.

These different aspects may be accounted for by the batch in ^¬ dexing approach of the present invention using a principle of equivalent deterioration. Particularly, it may be tested, how crucial the different aspects are and - by means of the batch indices - the quality of the powder portion may still be han ^¬ dled reliably. For example, if an exposure of a laser is 3 times as harmful, when the a portion of the powder bed had a small distance to the laser beam, a batch index of that par- ticular powder portion may be increased by an increment of 3 (in comparison to a powder portion having had a larger distance to the beam, for example) .

Figure 2 shows a schematic of a facility 200 comprising the manufacturing system 100 as described in Figure 1. Along with a description of Figure 2, an inventive quality control meth ^¬ od of a stock of base material is further described.

Although this is not explicitly indicated, the facility 200 may comprise even various manufacturing systems of the type as described or at least a plurality of different material lines of additive manufacturing, wherein a plurality of dif ^¬ ferent components 1 can be manufactured simultaneously in a plurality of build areas 50.

The facility 200 comprises a base material stock 30. The base material stock 30 is retained in a plurality of containers 15. Said containers 15 may be the same as the discharge or overflow container as described in Figure 1. Preferably, said containers 15 are metallic containers, each capable of grasp ^¬ ing e.g. 200 kg of base material and belonging to their fa ^¬ cility equipment. Preferably, fresh base material, e.g. per chased commercially may be present in plastic containers of e.g. amount of 10 kg, which base material may then be manual ^¬ ly filled into the containers 15. Alternatively, the contain ^¬ ers 15 may exhibit the mentioned plastic containers. The containers 15 may comprise a container number (not ex ^¬ plicitly indicated) . The date the respective one of the con ^¬ tainers 15 was filled with fresh powder may as well be regis ^¬ tered. Moreover, the type of base material or material compo ^¬ sition may be registered or indexed as per a quality control method and the control system 10 as will be described below.

As a mere example for the material stock 30 containers 15 are shown in Figure 2. Below the respective container 15, a sche ^¬ matic batch index of each of the containers is depicted. The left and the middle one of the depicted containers are as ^¬ signed to a batch index BI of "00" as these containers con ^¬ tain fresh base material, e.g. base material which has not been used previously. In contrast, the right container 15 of the stock 30 is not completely, but only partially filled with base material. Although this container might as well be assigned to batch index "00", it rather contains base material indexed with batch index BI of "01". The increment of 1 accounts for the fact that the respective base material has already been ex ^¬ posed to the manufacturing conditions in the manufacturing system 100 and a slight deterioration of 1 equivalent or in ^¬ crement is likely and has been assigned. Thus, this particu ^¬ lar base material 2 may be less suitable for a proximal manu- facturing job requiring base material of highest performance.

In order to manage or handle the idea of tracking the quality of the different powder portions by means of the batch index ^¬ ing, a control system 10 is provided pursuant to the present invention. The control system 10 may comprise the plurality of containers 15 as described. The control system 10 is fur ^¬ ther configured to track the base material and its quality during a plurality of manufacturing jobs in that the stock 30 is subdivided into the different batches of base material (cf . above) . The control system 10 further comprises a pro ^¬ cessing system 11 and a user or operator interface 20. The processing system 11 is connected to the operator interface 20 for receiving and processing instruction from an operator of the control system 10 and to display information to said operator .

Although this is not explicitly indicated, the facility 200 and/or the control system 10 may comprise a conveyor system being configured to convey base material to, e.g. between the different containers 15 and preferably in and out of the man ^¬ ufacturing system 100. According to the inventive method pertaining to the quality control or assurance of the stock 30 of base material 2, a user or operator may select a batch of base material out of a plurality of, possibly differently indexable or indexed batches of the stock 30. Actually, base material 2 with BI of "01" has been selected.

The operator may then load (either manually or by means of a respective instruction to the control system 10) a quantity of base material from the selected batch, e.g. material with BI "01", into the manufacturing system 100, more particularly to a specific build area 50 (cf. arrow) thereof.

Thus, the manufacturing job or additive manufacture of the component may be carried out from the selected base material 2. Once the component 1 has been built and finished, there will be some base material left or remaining in the manufac ^¬ turing system and/or build area (excess powder) which has to be sieved and thus assigned to an updated batch index BI as it has - at least partly - been exposed to the heat of the laser 8.

In the following, the already described aspects and possibly further aspect of the present inventive concept will be de- scribed more particularly in conjunction with a software module which may be executed by the described processing system 11 : Once a manufacturing job or build-up has been entered by the operator of the control system and/or the method, a "Post-Job Clean-up" may automatically be carried out by the control system or its software via the operator interface 20 in the control system 10. Preferably, there will always be such Clean-up-process for the control system 10 to capture the status of the base material 2 left or remaining in the build area 50 on the feed piston 5, after a component has been fin ^¬ ished . Then, the type of material and/or the name or indication of the respective manufacturing system 100 has to be entered by the operator into the control system via the operator interface 20. Preferably, the indication of the manufacturing sys ^¬ tem must be a valid name that matches one of the values which has been accorded to the manufacturing system previously.

Otherwise, an error message may be indicated in a display of operator interface 20, for example. Said indication of the manufacturing system or the respective machine name can pref ^¬ erably be selected from the drop-down list implemented in the respective software.

When there is no base material left in the feed piston 5 from a previous job, a value for the "Post-Job Clean-up" is pref ^¬ erably (assigned to) "0". When - on the contrary - there is base material left in the feed piston 5 from a previous job the mentioned value may e.g. as well be assigned to "0" by a user, when said remaining base material has been sucked out or removed from the machine manually. Then, as mentioned above, the amount and/or quantity of base material to be added to the feed piston of the machine is preferably entered by the operator. Following the process of filling the machine feed piston 5 with powder, the user may be provided with a list of containers from which the powder came. This list is preferably provided by the software and provided to the operator via the control system 10.

For example, the feed piston in Figure 5 has been filled com ^¬ pletely with 150 kg of a base material portion 2a. This was preferably taken from one of the containers 15 with batch in ^¬ dex BI "00" or from a fresh (commercially available) plastic container .

As maybe a number of 15 plastic containers (cf. numeral 15) may have been completely emptied, all of the information re ^¬ lated to them can be removed. If their contents were not be ^¬ ing completely depleted or emptied, the operator may simply update the respective values, e.g. pertaining to the contain ^¬ er number.

The total amount or quantity of base material in the selected batch, e.g. batch with batch index BI "00", is then preferably automatically recalculated after the portion of base ma ^¬ terial 2a has been loaded into the build area 50.

Next this base material 2a must be allocated to the actual manufacturing job. The quantity taken from each bucket or container 15 for a manufacturing job may be entered - into an appropriate column in the interface 20 of the control system 10.

Next, the respective component 1 may be manufactured as de ^¬ scribed according to Figure 1. Once the manufacturing job has been completed, any information for said job, as for instance a manufacturing job identification (ID) number may be generated and/or entered into the operator interface 20 by the op ^¬ erator . Once a value for a height of the feed piston 5 is entered, the remaining amount of powder on the feed piston 5 in the build area 50 (remaining from or after the previous manufac ^¬ ture) may automatically be calculated by means of the volume or partial volume of the container or build area. This proce ^¬ dure is carried out following:

For each batch, a check of each machines last manufacturing job is carried out by the control system 10 to see whether that manufacturing job has already assigned to an information or value of the amount of base material remaining in the build area 50 or if an end position of the feed piston 5 has been registered. If there is no such value, a job ID may be stored. Once said value has been accorded or registered, a search for a value for the position of the feed piston 5 at the end of the job is carried out.

In the present example, after the manufacture of the compo ^¬ nent 1 (cf. figure 1) e.g. 30 kg of base material may remain on feed piston 5 and or in the discharge or overflow container 15.

Actually, there are two types of base material which can be removed from the respective manufacturing system 100, i.e. base material remaining from the overflow piston or container 15 along with further base material which may always be pre ^¬ sent around the build platform 3 and base material remaining from the feed piston 5. The base material on the feed piston 5 can either be left in the machine for a subsequent manufacturing job or sucked out or off the feed piston 5. If the remaining base material is sucked out and removed, the operator will select one of the containers 15 and remove the powder from the machine or manu- facturing system by any suitable means. The mentioned removal is indicated in Figure 2 by the arrow pointing to the con ^¬ tainer 15 indexed with a BI of "02") . In other words: The quantity of base material that may have been removed from the overflow container 15, and possibly also from sites around the build platform 3, should be updated with respect to the corresponding batch index from a BI of "01" to "02", unless the expected quality deterioration of that portion or quanti- ty of base material is even worse and the batch index BI has to be updated by an increment of even 2 or 3 units (cf .

above) .

In other words, due to the exposure of base material in the build area 50 and on top of the feed piston 5, said base ma ^¬ terial has to be assigned a new batch index as well as fil ^¬ tered or sieved. During sieving, the base material passes normally from one container 15 to another. Once the base ma ^¬ terial has been sieved, the new container should be assigned with the next batch index number and the old "unsieved" con ^¬ tainer values should be removed or updated by the software, for instance.

When the next manufacturing job on the manufacturing system 100 is aimed and entered, the base material possibly left in the machine from the previous manufacturing job may be used, wherein the software and/or the control system 10 should in ^¬ form the user that this base material comprises a "used" batch index BI . Additionally or alternatively, the control system may propose a specific source of base material of any batch .

As the user is, in any case, informed about the quality or deterioration of the base material in the machine and/or the different containers of the stock 30, the operator may decide whether he wants to continue with a portion of base material with a batch index BI of "00", i.e. a fresh base material, e.g. for highest performance components or if he may manufac ^¬ ture the respective component with a base material of an al- ready updated or incremented batch index BI .

In the following further aspects and/or features of the de ^¬ scribed software are described: The software of the control system 10 may be an excel-based tool which is provided with the aim of allowing an SLM (or other powder based manufacturing) system to easily keep a track of their base material inventory as well as that one which has been used for past build jobs. Said software may be implemented with the aid of different columns and/or sheets, wherein with every selection/value change the control system 10 updates the information on the state of the manufacturing system(s) 100 as well as the base material via the sheets in order to keep the data overview up to date.

There are many features in place to guide the user through the process; such as messages when a selected manufacturing system or machine already contains base material from a cer ^¬ tain batch. Particularly, a planning tool may be provided which will assist the operator in deciding which base material and manufacturing system is available for the intended manufacturing job.

Further, an early warning system may be provided by means of which the quantity of base material remaining in one of the containers 15 may be registered and which will provide a warning and/or conduct a purchase, if the amount of base ma- terial there in gets below an alarm level. Thereby, a (sig ^¬ nificant) machine downtime due to lack of base material can advantageously removed or even completely avoided.

The presented control system 10 may particularly allow for the tracking of a multiplicity of differently indexable or indexed batches of base material in a plurality of additively manufacturing systems.

Furthermore, the (partial) stock 30 of each batch may be sur- veyed, in terms of the container number, weight of

base material in the container and/or the date the container was filled, as mentioned above. Moreover, the different con ^¬ tainers may be physically arranged or allocated in the facil- ity 200 or corresponding areas independent of the sieved and un-sieved condition. As well, the total amount of base mate ^¬ rial in the stock 30 may be indicated to the operator via the operator interface 20.

Once a machine is assigned to a new manufacturing job, sever ^¬ al checks may be carried out to check the state of the manu ^¬ facturing system 100. The user may see a pop-up message box, for example, if the state of the system is not as required e.g. if it contains base material from a batch other than the selected one.

The scope of protection of the invention is not limited to the examples given hereinabove. The invention is embodied in each novel characteristic and each combination of characteristics, which particularly includes every combination of any features which are stated in the claims, even if this feature or this combination of features is not explicitly stated in the claims or in the examples.