Effects of Thermal Deformation on Microstructure and Properties of Sintered Cu-10wt.%WC Composites

Abstract:

The Cu-10wt.%WC composite powder was prepared by reduction, and the Cu-10wt.%WC composite material was obtained by hot-pressing sintering, then hot rolled. Scanning electron microscope, X-ray diffractometer, transmission electron microscope and tensile test were used to study the effect and mechanism of hot rolling on the microstructure and properties of Cu-10wt.%WC composites. The results show that, after hot rolling, the WC particle size does not change but rearranges along the rolling direction in composites. The grain size of Cu decreases, and when the copper matrix recrystallizes, it grows preferentially along the (220) crystal plane, which reduces the misfit of the interface with the WC particles. After rolling, the tensile strength of the composites increased from 426MPa to 492MPa, the hardness increased from 149.7 HV0.2 to 166.8 HV0.2, and the electrical and thermal conductivity remained unchanged. Hot rolling can adjust the distribution of dislocations by rearranging WC particles, improve the bonding strength of Cu grains interface with WC particles, and strengthen the grain refinement, which improves the comprehensive properties of composites.

Key words:Cu-WC composite; hot pressing sintering; hot rolling; strengthening mechanism