Microstructure, interfacial reaction behavior, and mechanical properties of Ti3AlC2reinforced Al6061 composites

The interfacial reaction behavior of Al and Ti3AlC2at different pouring temperatures and its effect on the microstructure and mechanical properties of the composites were investigated. The results show that the addition of 3.0 wt.% Ti3AlC2refines the average grain size of α(Al) in the composite by 50.1% compared to Al6061 alloy. Morphological analyses indicate that an in-situ Al3Ti transition layer of ~180 nm in thickness is generated around the edge of Ti3AlC2at 720 °C, forming a well-bonded Al−Al3Ti interface. At this processing temperature, the ultimate tensile strength of Al6061−3.0 wt.%Ti3AlC2composite is 199.2 MPa, an improvement of 41.5% over the Al6061 matrix. Mechanism analyses further elucidate that 720 °C is favourable for forming the nano-sized transition layer at the Ti3AlC2edges. And, the thermal mismatch strengthening plays a dominant role in this state, with a strengthening contribution of about 74.8%.