APPARATUS FOR PRODUCING A THREE-DIMENSIONAL WORKPIECE WITH TEMPERATURE-CONTROLLED SHIELDING GAS

1 . An apparatus for producing a three-dimensional workpiece,

said apparatus comprising:

a carrier being arranged in a process chamber of the apparatus and adapted to receive a layer of raw material powder;

an irradiation device for selectively irradiating electromagnetic or particle radiation onto the raw material powder applied onto the carrier in order to produce the workpiece from said raw material powder by an additive layer construction method; and

a shielding gas supply system adapted to supply a shielding gas to the process chamber, and

a shielding gas control system that is adapted to control the temperature of the shielding gas.

2 . The apparatus according to claim 1 ,

wherein the shielding gas control system is adapted to raise the temperature of the shielding gas.

3 . The apparatus according to claim 1 ,

wherein the shielding gas control system is adapted to lower the temperature of the shielding gas.

4 . The apparatus according to claim 1 ,

wherein the shielding gas control system is adapted to control the temperature of the shielding gas prior to entering the process chamber and/or in the process chamber and/or after leaving the process chamber.

5 . The apparatus according to claim 1 ,

wherein the shielding gas control system comprises at least one temperature control element that is configured to act on the shielding gas to adjust the temperature thereof, said temperature control element being preferably configured as a heat exchanger.

6 . The apparatus according to claim 1 ,

wherein the shielding gas control system comprises a line circuit connecting a first and second temperature control element, the second temperature control element being configured to remove heat from the shielding gas and the line circuit being configured to transfer at least part of said heat to the first temperature control element for heating the shielding gas.

7 . The apparatus according to claim 1 ,

wherein the shielding gas control system is further adapted to control the flow rate of the shielding gas to and/or from the process chamber.

8 . The apparatus according to claim 1 ,

wherein the shielding gas control system is adapted to control at least one of the temperature and the flow rate of the shielding gas in response to at least one process parameter.

9 . The apparatus according to claim 8 ,

wherein said process parameter indicates a build height of the workpiece.

10 . The apparatus according to claim 1 ,

wherein the shielding gas control system is adapted to control at least one of the temperature and the flow rate of the shielding gas in response to at least one workpiece parameter relating to the workpiece to be produced by the apparatus.

11 . The apparatus according to claim 10 ,

wherein said workpiece parameter indicates at least one of the workpiece shape, and at least one workpiece dimension.

12 . The apparatus according to claim 1 ,

wherein the apparatus further comprises at least one of a heating unit and a cooling unit.

13 . The apparatus according to claim 12 ,

wherein the apparatus further comprises the heating unit, said heating unit being adapted to heat the carrier.

14 . Shielding gas control system for an apparatus, said apparatus being adapted to producing a three-dimensional workpiece and said apparatus comprising:

a carrier being arranged in a process chamber of the apparatus and adapted to receive a layer of raw material powder;

an irradiation device for selectively irradiating electromagnetic or particle radiation onto the raw material powder applied onto the carrier in order to produce the workpiece from said raw material powder by an additive layer construction method; and

a shielding gas supply system adapted to supply a shielding gas to the process chamber, wherein the shielding gas control system is adapted to control at least one of the temperature and the flow rate of the shielding gas in order to raise the temperature of the shielding gas.

15 . A method of operating an apparatus to produce a three-dimensional workpiece said method comprising:

receiving a layer of raw material powder with a carrier arranged in a process chamber of the apparatus;

selectively irradiating electromagnetic or particle radiation onto the raw material powder applied onto the carrier in order to produce the workpiece from said raw material powder by an additive layer construction method;

supplying a shielding gas to the process chamber from a shielding gas supply system, and

controlling at least one of the temperature and the flow rate of the shielding gas to raise the temperature of the shielding gas.

16 . The apparatus according to claim 9 , wherein the shielding gas control system is adapted to raise the temperature of the shielding gas with an increasing build height.

17 . The apparatus according to claim 11 , wherein said workpiece shape is defined by a cross-sectional shape.

18 . The apparatus according to claim 12 , wherein the shielding gas control system is adapted to control at least one of the temperature and the flow rate of the shielding gas in response to an operating state of at least one of the heating unit and the cooling unit.