Microstructural characterization of MWCNTs/magnesium alloy composites fabricated by powder compact laser sintering

Multi-walled carbon nanotubes (MWCNTs)/magnesium alloy (AZ91D) composites have fabricated by the powder compact laser sintering process. It is found that, when the laser output power is 500 W, the composites are sintered thoroughly because of the fully dense and uniform cross-sectional microstructures, and produced grain refinement and high microhardness compared with monolithic AZ91D. Meanwhile, MWCNTs bonded well with the matrix can survive in the liquid magnesium matrix during the laser melting process, showing the pull-out strengthening effect in the fracture surface. These results indicate that MWCNTs can increase the laser absorption of the MWCNTs/AZ91D composites compare with monolithic AZ91D, and provide high temperature and cooling rate to make the composites tough.