Generative manufacturing of components with a heatable building platform and apparatus for implementing this method

Patent metadata

Field	Value
Publication number	US-11279082-B2
Application number	US-201716072578-A
Country	US
Kind code	B2
Filing date	Jan 4, 2017
Priority date	Jan 28, 2016
Publication date	Mar 22, 2022
Grant date	Mar 22, 2022

Abstract

Various embodiments may include a method for the generative manufacturing of a component on a building platform comprising: applying particles of a building material layer by layer to the building platform and then to the component under construction; fusing the applied particles with an energy beam; and heating the component under construction with a heating device associated with the building platform. A reference temperature Tr for each layer produced and a tolerance range for the reference temperature Tr are defined. A heating power of the heating device is lowered as sequential layers are fused to the extent that the tolerance range for a reference temperature Tr is maintained in a last layer produced.

First claim

What is claimed is:

1. A method for the generative manufacturing of a component on a building platform, the method comprising:
applying particles of a building material in an active layer to the building platform and then to the component under construction;
fusing the particles in the active layer using an energy beam;
calculating an expected temperature of a final layer at completion of the component;
heating a first layer of the building material to the expected temperature with a heating device embedded in the building platform, the first layer in physical contact with the building platform and opposite the active layer of the component;
wherein calculating the expected temperature depends at least in part on a nominal power of an energy beam and an amount of reflected energy based on characteristics of the particles;
wherein a reference temperature T r for each layer produced and a tolerance range for the reference temperature T r are defined;
and
lowering a heating power of the heating device as sequential layers are fused to the extent that the tolerance range for a reference temperature T r is maintained in the final layer.

2. The method as claimed in claim 1 , further comprising controlling the heating power with an open-loop control depending at least in part on a fusing power of the energy beam and the heat conducting properties of the component.

3. The method as claimed in claim 2 , further comprising calculating the fusing power from the nominal power of the energy beam and switching-off time intervals of the energy beam as a reduction of the fusing power with respect to the nominal power.

4. The method as claimed in claim 2 , further comprising adjusting the calculations based on heat conducting properties in the form of a thermal resistance or a coefficient of thermal conductivity of the component.

5. The method as claimed in claim 1 , further comprising heating the first layer of the component under construction to a temperature level at least as high as a calculated or experimentally determined heating of the uppermost layer of the component completed without using the heating device.

6. The method as claimed in claim 5 , further comprising calculating heating of the uppermost layer of the completed component with the following model:
T 1 =T 0 +R th ·P S
where T 1 is the temperature of the completed component, T 0 is the starting temperature of the building platform without heating, R th is the thermal resistance of the completed component and P S is the fusing power of the energy beam.

7. The method as claimed in claim 1 , further comprising a closed-loop control, including measuring a surface temperature of the component being manufactured as a controlled variable for lowering of the heating power of the heating device;
wherein measuring the surface temperature is carried out outside a melt bath produced by the energy beam or during switching-off time intervals of the energy beam.

8. The method as claimed in claim 7 , further comprising determining the surface temperature of the component under construction by measuring the thermal radiation emanating from the surface of the workpiece.

9. The method as claimed in claim 2 , further comprising a closed-loop control for a measured surface temperature of the component under construction;
wherein measuring the surface temperature is carried out outside a melt bath produced by the energy beam or during switching-off time intervals of the energy beam; and
the rate of lowering the heating power prescribed by the open-loop control is corrected if the measured surface temperature does not correspond to the reference temperature.

10. The method as claimed in claim 9 , further comprising implementing a correction interval for correcting the rate of lowering the heating power.

11. The method as claimed in claim 9 , further comprising determining the surface temperature of the component under construction by measuring thermal radiation emanating from the surface of the component.

Assignees

• Siemens Ag

Inventors

• Reznik Daniel

Classifications

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F12/17

  to heat the build chamber or platform · CPC title

• B22F12/10

  Auxiliary heating means · CPC title

• B22F10/368

  Temperature or temperature gradient, e.g. temperature of the melt pool · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title