Thermal Post-Processing in Additive Manufacturing | Carbolite Gero GmbH & Co. KG
Dr. Timm Ohnweiler, Vice president,
Carbolite Gero GmbH & Co. KG
In addition to the forming process itself (injection molding, 3-D printing, lithography, etc.), heat treatment is an often underestimated production step in order to obtain optimum component properties. Best temperature uniformity and a targeted gas flow, especially in the debinding phase, are the keys to distortion-free dimensionally stable components. Especially in medical, automotive and aerospace applications, precision components are subject to ever-increasing demands with regard to their geometric and mechanical properties.
Therefore, a new generation of debinding and sintering units was developed. The new and further development of the products is always based on a close cooperation with research and development, especially in the field of additive manufacturing, as well as on the experience of our customers.
The presentation gives an overview of the new generation of equipment for debinding, residual debinding, annealing and sintering. Direct additive processes, such as laser powder-bed-fusion (L-PBF), require a final heat treatment of the parts in order to relieve the stresses arising in the microstructure. Indirect additive manufacturing processes require several heat treatment steps: In chemical debinding, a solvent reacts with the main binder. Temperatures between 50°C and 120°C are required here. Purely thermal debinding is often carried out in temperature ranges between 300°C and 600°C, often also under vacuum. The parts are then sintered at a temperature slightly below the melting point. Depending on the material, temperatures of 1000°C to 1500°C and modified atmospheres are required here.
These systems and their applications are briefly presented. The results of the analytical calculations as well as the FEM simulations for the optimal inert gas flow are presented, which led to a new generation of MIM sintering furnaces (type HTK-MIM|CIM|AM).