Preparation and mechanical properties of TiCx-Ni3(Al,Ti)/Ni composites synthesized from Ni alloy and Ti3AlC2 powders

In this work, a novel TiCx-Ni3(Al,Ti)/Ni alloy composite was successfully synthesized from Ti3AlC2 (20 vol% and 40 vol%) and Ni starting powders via in-situ hot-pressing route at 1200 °C under 30 MPa. As the interleaved Al atoms diffused out from Ti3AlC2 nanolayers, Ti3AlC2 decomposed into nonstoichiometric nano-TiCx particles while the additional Al and fractional Ti atoms reacted with Ni matrix to form Ni3(Al,Ti). Due to the homogeneous distribution of ultrafine TiCx and Ni3(Al,Ti) particles in Ni matrix, Hardness, flexural strength and fracture toughness of the composite reinforced with 20 vol% of Ti3AlC2 increased 50%, 50% and 70%, in comparison with the pure Ni alloy prepared under the same condition. In addition, the positive temperature dependence of flexural strength was detected in 40vol%Ti3AlC2-Ni alloy sample in the temperature range of 20 °C and 700 °C, and the maximum of flexural strength could reach 989±28 MPa at 700 °C.