Preparation and Properties of ZrB<sub>2</sub>-Cu Composites by Spark Plasma Sintering

Abstract

For high thermal conductivity and high electrical conductivity, copper is a good electrode material. The wearing resistance and spark resistance of Cu can be improved with the addition of ZrB2. ZrB2-Cu composites with high Cu volume fraction was successfully prepared by spark plasma sintering (SPS) process in this paper. The microstructure and properties of the sintered samples were characterized. The effect of the sintering temperature and the ZrB2 content in composites on the relative density and properties of the composites were investigated. The results show that the relative density and mechanical properties increase with the sintering temperature increasing. The optimum sintering temperature is 900 °C for 10wt.% ZrB2-Cu, 1000 °C for 20wt.% ZrB2-Cu and 1050 °C for 30wt.% ZrB2-Cu. With the ZrB2 content in composites increasing from 10wt.% to 30 wt.%, the electrical resistivity increases from 2.25×10-6 Ω.cm to 8.82×10-6 Ω.cm, the flexural strength decreases from to 539.1 MPa to 482.2 MPa and the fracture toughness decreases from to 15 MPa.m 1/2 to 9 MPa.m 1/2. The hardness (HV) of ZrB2-Cu composites is significantly enhanced by the ZrB2 particulate reinforcement, increasing from 1410 MPa for 10 wt.% ZrB2 to 2480 MPa for 30wt.% ZrB2.