In-situ synthesis of a novel multiphase reinforced Al-matrix composite prepared from A6061 alloy and a small amount of MXene

Abstract

A novel in-situ multiphase reinforced Al matrix composite (AMC) was synthesized by combining spark plasma sintering (SPS), hot extrusion, and subsequent T6 treatment using A6061 alloy and a small amount of MXene as the starting materials. Although the MXene was randomly distributed in the as-SPSed composite, it was preferentially oriented along the extrusion direction after extrusion. During T6 treatment, the MXene was decomposed into Ti and C, and its oxygen-containing functional groups reacted with Mg in the A6061 to form MgO. The reinforcing phases including MgO, Mg₂Si, TiC and Q′ were uniformly distributed in the Al alloy matrix. The hardness, yield strength, and ultimate tensile strength of the peak-aged AMC were 115 HV, 329 MPa, and 355 MPa, respectively, which are 10.9 %, 12.7 %, and 6.6 % higher than those of the peak-aged unreinforced A6061 alloy. This work provides new insights for designing in-situ multiphase reinforced AMC with excellent mechanical performance.