Direct laser sintering of aluminum matrix composites

In the present work, we used direct metal laser sintering (DMLS) process to fabricate Al-SiC composite parts directly from a three-dimensional CAD model. Al-7Si-0.3Mg powders were blended with various amounts of SiC particles (5, 10, 15, 20 vol%) at two different sizes (7 and 17 m) and subjected to direct laser sintering using a 200 W continuous wave CO2 laser beam at various scan rates. The densification and microstructural features of the laser-sintered parts were studied. It is shown that the highest density is obtained for the Al alloy-5% SiC (7 m) composite powder. The melt stability is also found to be improved in the presence of SiC particles. The microstructure of the laser-sintered parts composed of -Al, primarily silicon, SiC, and Al4SiC4 three dimensional plates. This paper presents the advantages and barriers of using DMLS for the fabrication of complex-shaped parts from Al matrix composite powders.