Microstructure, interfacial reaction behavior, and mechanical properties of Ti3AlC2 reinforced Al6061 composites

The interfacial reaction behavior of Al and Ti3AlC2 at 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.% Ti3AlC2 refines the average grain size of alpha(Al) in the composite by 50.1% compared to Al6061 alloy. Morphological analyses indicate that an in-situ Al3Ti transition layer of similar to 180 nm in thickness is generated around the edge of Ti3AlC2 at 720 degrees C, forming a well-bonded Al-Al3Ti interface. At this processing temperature, the ultimate tensile strength of Al6061-3.0 wt.%Ti3AlC2 composite is 199.2 MPa, an improvement of 41.5% over the Al6061 matrix. Mechanism analyses further elucidate that 720 degrees C is favourable for forming the nano-sized transition layer at the Ti3AlC2 edges. And, the thermal mismatch strengthening plays a dominant role in this state, with a strengthening contribution of about 74.8%.