Material Issues for Direct Rapid Prototyping utilizing the Blown Powder Process (BPP)

摘要

Direct material build-up via laser sintering is promising to give convenient and quick access to components of complex shape, made of difficult-to-consolidate materials, including metalon-metal combinations. A high and sharp melting point, and a high thermal conductivity are factors narrowing the operational window of this process. A coarse powder, high feed rates, continuous and high laser power can shorten the build-up cycle, but at the same time impair the surface quality. So far achieved: automated fabrication of individual prototypes with structural functionability, complete consolidation of alloys and material combinations - even with "incompatible" constituents, and tailoring of composition, gradients and microstructure. The challenges on the way to wider application and commercialization include supply of suitable and inexpensive (composite) powders, reliable and adjustable powder feed/yield, higher build-up rates, and finally a better interface to CAD design and overall process control.