Effect of Sintering Temperature on Microstructure and Properties of ZrW2O8/Al Composite Prepared by SPS

Abstract:

50%ZrW₂O₈/Al composites were prepared by spark plasma sintering. The effect of sintering temperatures on the microstructure, phase composition, density, thermal expansion coefficient and thermal conductivity of the composites was studied. The results show that the composites sintered at different temperatures contain γ-ZrW₂O₈. As the sintering temperature gradually increases from 475 ℃ to 575 ℃, the density and content of γ-ZrW₂O₈ in the composites gradually increase. After a process of stress relief by the first thermal expansion test from room temperature to 300 °C, the content of γ-ZrW₂O₈ in the composite material is significantly reduced. The second thermal expansion test reveals that as the sintering temperature increases, the thermal expansion coefficient first increases and then decreases, with the sample sintered at 525 °C being the highest (4.6×10^–6 K^–1). The sintering density of the composite significantly affects its performance. The ZrW₂O₈/Al composite sintered at 525 °C presents both the highest density (92.9%) and thermal conductivity (31.9 W/m·K). 525 ℃ is the optimal sintering temperature that takes into account the composition stability and sintering density of the composites.