Laser microstructuring of composite powder materials

This paper describes two processes for the microstructuring of carbide and boride cermets by laser microcladding/selective sintering using a pulsed Nd:YAG laser. The first part deals with the microcladding of carbide cermet [Cr₃C₂-NiCr] with varying percentage content of metal carbide [Cr₃C₂]. The results show that as the metal carbide content decreased from 70% to 50% of its value; cracks are reduced but the hardness decreased considerably. The second part discusses the selective laser sintering of boride cermets. The results show that liquid phase sintering seems to be more effective, in which the metallic part NiMo acts as a binder to the metal boride counterpart [(MoW)₂NiB₂]. From the microstructure analysis it appears that the Ni-Mo metal has formed a film on the boride resulting in agglomeration of the particles