Study on Microstructure and Mechanical Properties Modification of Cu-Ti3AlC2 Composites by Ni Element

Abstract

Ti3AlC2 three-layered ceramics-reinforced copper matrix composites show not only the strength of the copper matrix but also better wear resistance, all while preserving its conductive property and, ultimately, reducing the cost of preparation. However, decomposition in Cu-Ti3AlC2 composites mainly occurs due to the severe interdiffusion of Al and Cu elements from Ti3AlC2 particle-grain boundaries, leading to the formation of TiCx. This work explored a practical method to produce Cu reinforced with a Ti3AlC2 particle which keeps an effective ternary layered structure by adding a nickel element. Results show that the addition of Ni elements results in a microstructure composed of Ti3AlC2, TiCx, NixAl, NixTi, and a Cu(Ni) matrix in the Cu-Ni-Ti3AlC2 composites. As the volume fraction of Ti3AlC2 particles increases, the morphologies change from a finely dispersed reinforcement phase to a continuous network, leading to a reduction in hole number and volume compared to Cu-Ti3AlC2 composites. This reduction is especially significant when the volume fraction of Ti3AlC2 exceeds 50%. The formation of NixAl and NixTi compounds at the grain boundary of the reinforcement phase after Ni element alloying restricts the diffusion of Al elements. The addition of Ni elements improves the mechanical properties of the composites.