Method and device in particular for generatively producing and coding a three-dimensional component

Abstract

The invention relates to a method for producing, in particular generatively producing, and coding a three-dimensional component. Said method comprises the following steps: providing a starting material, supplying a process gas to the starting material, melting the starting material by means of a heat source, and repeating the aforementioned steps. The method according to the invention is characterized in that, at least at a predetermined time interval during the melting of the starting material, a coding component or a coding gas containing a coding component is added to the process gas such that the use of the coding component in the finished object is detectable, and coding information is logged which describes the coding information and the location thereof in the component.

Claims

1. A method for producing and coding a three-dimensional component, comprising: providing a metal starting material; supplying a process gas to the starting material; melting the starting material with a heat source; and repeating the above steps until completion of the three-dimensional component, wherein, during at least at a predetermined time interval of the melting of the starting material, a gaseous coding component is added to the starting material and the coding component is integrated into the three-dimensional component such that the coding component is detectable in the three-dimensional component and the three-dimensional component is thereby coded, and wherein the gaseous coding component comprises at least one isotope of at least one gas, and content of the at least one isotope is changed in comparison to a naturally occurring content of the at least one isotope in the at least one gas, said method further comprising logging information about the coding component.

2. The method of claim 1, wherein the process gas comprises an inert gas, an active gas, or both an inert gas and an active gas, and wherein said inert gas is selected from argon, helium, neon, krypton, xenon, and radon, said active gas is selected from O.sub.2, CO.sub.2, H.sub.2 and N.sub.2, and mixtures thereof, and the coding component comprises oxygen 18 carbon dioxide (C.sup.18O.sub.2), carbon 13 carbon dioxide (.sup.13CO.sub.2), carbon 13 carbon monoxide (.sup.13CO), deuterium (D.sub.2), nitrogen 15 (.sup.15N.sub.2) and oxygen 18 (.sup.18O.sub.2), and mixtures thereof.

3. The method of claim 2, wherein the process gas comprises the inert gas.

4. The method of claim 2, wherein the process gas comprises the active gas.

5. The method of claim 1, wherein the frequency of the at least one isotope relative to the naturally occurring frequency is elevated or diminished by more than 0.5%.

6. The method of claim 1, wherein the coding component comprises at least one isotope of an active gas, which reacts with the material of the component to be produced in such a way as to remain in the component.

7. The method of claim 1, wherein the coding component comprises a plurality of different isotopes in predetermined ratios, wherein the plurality of different isotopes in predetermined ratios in the coding component comprise the coding.

8. The method of claim 1, wherein the at least one isotope comprises isotopes of a gas that is a primary component of the process gas.

9. The method of claim 1, wherein the coding component comprises a gaseous alloying element, wherein content of the gaseous alloying element is selected such that the gaseous alloying element only negligibly changes material properties of the three-dimensional component.

10. The method of claim 1, wherein the logging of information about the coding component comprises storing of the information in a database.

11. The method of claim 1, wherein the information about the coding component is used to detect the three-dimensional component via detection of the coding component by a chemical analysis process or a mass spectrometer.

12. The method according of claim 1, wherein the metal starting material is provided in a form of a powder feed or wire feed, and the heat source is a laser beam, an electron beam, or a plasma/electric arc.

13. The method of claim 1, wherein the coding component comprises at least one isotope of an inert gas, wherein the isotope is integrated into the component.

14. The method of claim 1, wherein the at least one isotope is different from isotopes in the process gas.

15. The method of claim 1, wherein the coding information contains at least one of the following: information about the form of the coding component, information about the content of the coding component, information about location of the coding component in the three-dimensional component, and information about a serial number of the three-dimensional component.

16. The method of claim 1, wherein the coding component is not integrated throughout the three-dimensional component.

17. The method of claim 16, wherein the coding component is only integrated into one or more predetermined locations or areas of the three-dimensional component.

18. The method of claim 17, wherein the coding component is only integrated into a plurality of predetermined locations or areas of the three-dimensional component, and each of said locations or areas are geometrically separate from each.

19. The method of claim 1, wherein said at least one isotope is one or more isotopes selected from nitrogen 15, nitrogen 14, carbon 12, carbon 13, carbon 14, oxygen 16, oxygen 18, argon 36, argon 38, argon 39, argon 40, hydrogen 3, helium 3, and helium 4.

20. The method of claim 1, wherein said coding component is selected from oxygen 18 carbon dioxide (C.sup.18O.sub.2), carbon 13 carbon dioxide (.sup.13CO.sub.2), carbon 13 carbon monoxide (.sup.13CO), nitrogen 15 (.sup.15N.sub.2) and oxygen 18 (.sup.18O.sub.2), and mixtures thereof.

21. A device for producing three-dimensional components, comprising: a building platform on which a starting material can be provided; a process gas feeding device for supplying a process gas; a heating source for melting the starting material; and a coding component feeding device that is connected with a control device for supplying a gaseous coding component or a coding gas containing a gaseous coding component to the starting material at least at a predetermined time interval during the melting so that the coding component in the three-dimensional component is detectable, and a database for storing coding information, wherein the gaseous coding component comprises at least one isotope of at least one gas, and content of the at least one isotope is changed in comparison to a naturally occurring content of the at least one isotope in the at least one gas.

22. The device of claim 21, further comprising a processing chamber.

23. The device of claim 21, wherein the coding component feeding device comprises a mixing chamber for mixing the coding component into the process gas, wherein process gas or a mixture of process gas and coding component can be supplied to the processing chamber from the mixing chamber.

24. The device of claim 21, further comprising a control device comprising a coding component regulating device with a closed control loop for regulating the supply of coding component, and a sensor which is used to acquire a value for at least one volume flow in the processing chamber or the mixing chamber and compare the at least one volume flow with a prescribed desired value, after which the prescribed desired value is set by an actuator.

25. The device of claim 21, wherein the coding component feeding device comprises a gas storage container that contains both process gas and a corresponding content of coding component.

Description

(1) The invention will be explained in more detail below based on a FIGURE. Shown on;

(2) FIG. 1 is a schematic view of a device according to the invention.

(3) A device 1 for generatively producing and coding a three-dimensional component is described below. As already mentioned, nearly any device 1 for generatively producing three-dimensional components is basically suitable for implementing the method according to the invention.

(4) The invention will be exemplarily explained in a general form based on a laser-melting device 1 with a powder bed (FIG. 1).

(5) The laser-melting device consists of a processing chamber 2, which is outwardly closed by a chamber wall 3 and borders a processing area 4. The processing chamber 2 serves as an assembly space for the three-dimensional component.

(6) Arranged in the processing chamber 2 is an upwardly open container 13. Situated in the container 13 is a building platform 5 for accommodating the component 6 to be produced. The building platform 5 has a height adjustment device, which can be used to vertically adjust the building platform 5 in such a way that a surface of a layer to be newly hardened is arranged in a working plane.

(7) The device 1 further consists of a storage container 7. The storage container 7 is designed to hold a hardenable, powdery starting material.

(8) Further provided is an application device 8 for applying the starting material to the building platform 5. Such an application device 8 can be moved in a horizontal direction parallel to the working plane.

(9) Additionally provided is a laser 9 for generating a laser beam or a heat source. A laser beam generated by the laser 9 is deflected by a deflecting device 10, and focused by a focusing assembly (not shown) on a predetermined point directly below the working plane. The deflecting device 10 can be used to change the progression of the laser beam in such a way as to melt the locations of the applied layer that correspond to the cross section of the object to the produced.

(10) Additionally provided is a process gas feeding device 11, which can be used to expose the processing chamber 2 to a process gas.

(11) The process gas feeding device 11 has a storage container for the process gas, wherein the process gas storage container (not shown) is connected with the processing chamber 2 via a line section.

(12) Further provided is a coding component feeding device 12, which can be used to expose the processing chamber 2 to a coding component.

(13) The coding component feeding device has a storage container (not shown) for the coding component. The latter is connected with the processing chamber 2 via a line section.

(14) A mixing chamber (not shown) can alternatively be provided. The mixing chamber has an inlet for supplying a process gas from the storage container for process gas and an inlet for supplying a coding component from the storage container for the coding component.

(15) The process gas and coding component can also be provided as a pre-mixture (premix) from a gas storage container (not shown), which contains both process gas and a corresponding content of coding component. This gas storage container containing the premix then comprises the coding component feeding device, and is connected directly with the processing chamber 2 in addition to the storage container for the process gas, or with the mixing chamber.

(16) Further provided is a control device (not shown) for controlling the addition of the coding component. The control device consists of a coding component regulating device with a closed control loop, which regulates the addition. The coding component regulating device can consist of a P-regulator, an I-regulator, a D-regulator and combinations thereof, e.g., a PID regulator. The coding component regulating device uses a sensor to acquire an actual value for the one or several volume flows in the processing chamber 2 and/or mixing chamber, compares it with a prescribed desired value for one or several volume flows, after which the prescribed desired value is set by way of an actuator.

(17) A method according to the invention will be described below based on an exemplary embodiment.

(18) In the first step, a metal starting material is here applied or provided on the building platform 5 in the form of a powder bed by means of the coating device. Alternatively, the metal starting material can also be supplied by means of a powder feed or a wire feed.

(19) In a second step, an inert protective gas such as nitrogen is then supplied to the processing chamber 2 as the process gas by means of the process gas feeding device 11.

(20) In a subsequent step, the starting material is melted by means of the laser 9.

(21) Since the melted volume is as a rule rather small in nearly all generative methods, the layer is cooled while the laser melts material at another location or even while a new powder layer is being applied.

(22) In addition, a stabilizing step can be provided in specific processes, in which the layer is cooled and hardened.

(23) These steps are repeated.

(24) The coding component is then supplied to the processing chamber, either continuously or at a predetermined time. As a rule, process gas is permanently located in the processing chamber. The buildup process as a rule only starts once the requirements for O.sub.2 and H.sub.2O content have been met. If the process gas is nitrogen or a nitrogen-containing mixture (with the same holding true for argon), then the process gas can contain a coding component of a kind where the content of nitrogen 15 and nitrogen 14 isotopes relative to the natural content of nitrogen 15 and nitrogen 14 isotopes or their correlation has been changed. With respect to nitrogen, for example, the ratio of .sup.15N (frequency=99.34) to .sup.15N (frequency=0.366) is changed in such a way that the content of .sup.15N is elevated, and the content of .sup.15N is diminished (or vice versa).

(25) The coding component imparts a unique isotope signature to this area of the component.

(26) In additional layers of the component, the original process gas can be used once again, which contains no coding component.

(27) The coding of the component with a coding component can be repeated, so that varying layers or areas on the component are coded. Coding areas requires that the process of producing a layer be interrupted, the atmosphere in the processing chamber be changed or the process gas composition be changed, and the residual layer be produced. This step must be correspondingly repeated for ensuing layers, so that an area of the component is then coded.

(28) Use can here be made of the same respective coding component, or different coding components can also be used.

(29) The coding information is stored in a database.

(30) All parameters necessary for producing the three-dimensional component are also electronically stored.

(31) The coding component feeding device can be connected with an interface of the device in such a way as to precisely store at what time or predetermined time interval in melting the starting material that a coding component is allocated to the protective gas. This makes it possible to precisely determine or detect where the coding is arranged in the component.

(32) This coding information can advantageously also be linked with the serial numbers of the component.

(33) For example, it is possible in a first series of components to produce the lowermost layer or lowermost layers while adding a coding component. In another series of components, other layers can then be produced with the coding component. For a single series of components, this makes it possible to code the latter at different locations.

(34) Varying the coding of an individual series makes it even more difficult for forgers to falsify the coding.

(35) According to the invention, the used isotopes can be isotopes of the protective gas, i.e., for example when using nitrogen as the protective gas, the ratio between nitrogen 15 and nitrogen 14 isotopes is changed. For example, carbon dioxide containing carbon 12, carbon 13 and carbon 14 isotopes can also be provided.

(36) For example, argon, oxygen isotopes and nitrogen isotopes can be combined while producing components out of aluminum.

(37) While producing components out of stainless steel or nickel-based alloys, a combination of carbon isotopes in CO.sub.2 and hydrogen isotopes in H.sub.2 can be used.

(38) Inert isotopes can in principle be used independently of material, since embedding into the microporosities is a purely mechanical process.

(39) However, it is also possible to add other isotopes of another gas together with a content of this other gas to the protective gas as the coding component.

(40) In an ensuing step, the finished three-dimensional component can be analyzed with the help of a detection device, for example a mass spectrometer (gas chromatograph), so as to in so doing check the coding or originality of the component. An analysis can also be performed via magnetic resonance or using chemical analytical methods.

(41) Another exemplary embodiment of the method according to the invention provides a gaseous alloying element as the coding component.

(42) For example, it can here be provided that an inert gas such as argon be used as the process gas, which contains a small portion of between 1 ppm and 10,000 ppm of nitrogen 15 as the coding component. The metal starting material contains titanium. During the production of the three-dimensional component, a small portion of the titanium thus reacts with the nitrogen 15, and yields titanium nitride 15. The latter is indistinguishable from titanium nitride 14 in terms of its chemical and physical properties, and therefore cannot be detected by means of a chemical analysis method. However, it is possible to analyze the component with a mass spectrometer. It is then determined that the component under a nitrogen atmosphere was produced with an elevated nitrogen 15 content.

(43) As a consequence, the method according to the invention can be used to code specific areas or layers of a three-dimensional component, and to then detect this coding.

REFERENCE LIST

(44) 1 Device 2 Processing chamber 3 Chamber wall 4 Processing area 5 Building platform 6 Component 7 Storage container 8 Application device 9 Laser 10 Deflecting device 11 Process gas feeding device 12 Coding component feeding device 13 Container