Grain Refinement and Mechanical Properties of Cu-Cr-Zr Alloys with Different Nano-Sized TiC Addition.

The TiC/Cu master alloy was prepared via thermal explosion reaction. Afterwards, the nano-sized TiC/Cu master alloy was dispersed by electromagnetic stirring casting into the melting Cu-Cr-Zr alloys to fabricate the nano-sized TiC-reinforced Cu-Cr-Zr composites. Results show that nano-sized TiC can effectively refine the grain size of Cu-Cr-Zr alloys. The morphologies of grain in Cu-Cr-Zr composites changed from dendritic grain to equiaxed crystal because of the addition and dispersion of nano-sized TiC. The grain size decreased from 82 to 28 μm with the nano-sized TiC content. Compared with Cu-Cr-Zr alloys, the ultimate compressive strength (σ) and yield strength (σ) of 4 wt% TiC-reinforced Cu-Cr-Zr composites increased by 6.7% and 9.4%, respectively. The wear resistance of the nano-sized TiCp-reinforced Cu-Cr-Zr composites increased with the increasing nano-sized TiCp content. The wear loss of the nano-sized TiC-reinforced Cu-Cr-Zr composites decreased with the increasing TiC content under abrasive particles. The eletrical conductivity of Cu-Cr-Zr alloys, 2% and 4% nano-sized TiCp-reinforced Cu-Cr-Zr composites are 64.71% IACS, 56.77% IACS and 52.93% IACS, respectively.