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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.

Sm2Zr2O7 is one of the promising candidate materials for the next generation thermal barrier coatings because of its excellent thermal properties. But at high temperature the thermal conductivity of rare-earth zirconate increases because of radiation conduction. NiCr2O4, which can absorb the infrared photons intensely, was introduced to reduce the radiation conduction of rare-earth zirconate. NiCr2O4 powder was prepared by coprecipitation. The bulks of Sm2Zr2O7— NiCr2O4 with different content of NiCr2O4 were prepared by using non-pressure sintering. The phase and microstructure of the samples were characterized by XRD and SEM. The optical absorption was also investigated. The absorptivity of the composite, which was generally higher than that of pure Sm2Zr2O7 prepared by coprecipitation and non-pressure sintering, was enhanced with the content of NiCr2O4 increasing. The enhancement of absorptivity will reduce the radiation conduction of rare-earth zirconate potentially.