The effect of heat treatment on the microstructure and mechanical properties of Ti2AlC/Inconel 718 composite material formed by Selective Laser Melting

Ti2AlC/Inconel 718 composites were prepared by Selective Laser Melting process.The effects of different heat treatment processes on the microstructure and mechanical properties of the composites were studied. The results show that the micro-hardness and tensile strength of the samples after double aging (DA) treatment are improved significantly due to the precipitation of γ'and γ" phases, but the elongation and the reduction of area of the samples after fracture are decreased due to the increase of strength and insufficient dissolution of the deposited Laves phase. After solid solution treatment (SA) and homogenization + solid solution aging (HSA) treatment, recrystallization occurred, which offset the rapid solidification structure obtained by Selective Laser Melting process. At the same time, due to the precipitation of needle-like δ phase at the grain boundary, the strengthening element Nb is consumed, and the precipitation of γ''and γ' phases is reduced. Compared with the direct double aging treatment, the strength of the samples decreased significantly and the plasticity increased.