Effects of 2D Ti3C2Tx (Mxene) on mechanical properties of ZK61 alloy

Two-dimensional Ti3C2Tx (Mxene) is a new attractive reinforcement in composites due to its high aspect ratio and rich surface functional groups, but in metal matrix composites the enhancement of Ti3C2Tx is far from expectation, which is due to its poor thermal stability and oxidation resistance. To reveal the performance of Ti3C2Tx in magnesium matrix composites, ZK61 alloys reinforced with Ti3C2Tx are fabricated by spark plasma sintering, which are conducted at low sintering temperatures with a relatively short sintering time to maintain the stability of Ti3C2Tx. With 0.5 wt% Ti3C2Tx, the hardness increased by 5.4%, the compressive yield strength (CYS) increased by 28.7% and the failure strain decreased by 6.1%. The Ti3C2Tx shows a relatively high strengthening efficiency and a similar performance as graphene. The Ti3C2Tx distributes uniformly in the grain boundary and is surrounded by the in-situ synthesized MgO nanoparticles, which distribute disorderly in the interface between the Ti3C2Tx and the alpha-Mg matrix. When the Ti3C2Tx content increases to 1.0 wt%, the hardness and CYS increased further, but the failure strain decreased by 70.7%. The Ti3C2Tx clusters and thicker grain boundary resulted in the grain boundary embrittlement and induced the intergranular fracture, which resulted in the decrease of the strain hardening and uniform elongation. (C) 2021 Elsevier B.V. All rights reserved.