High-pressure and high-temperature synthesis and study of the thermal properties of ZrW2O8/Cu composites

ZrW2O8/Cu composites with high thermal conductivity and low coefficients of thermal expansion (CTE) are desired to be utilized in thermal management applications. The ZrW2O8/Cu composites were synthesized under high-pressure and high-temperature (HPHT) conditions and annealing method. We found that the thermal conductivity and CTE of the ZrW2O8/Cu composites could be controlled through suitable HPHT sintering. In addition, cyclic heating-cooling is crucial to recrystallize the composite and reduce the thermal mismatch stress to produce a composite with high thermal conductivity and a low CTE. Under HPHT (3 GPa, 500 °C) conditions and annealing at 700 °C, the thermal conductivity and CTE of the ZrW2O8/Cu composites have been determined directly to 165 W/(m k) and 6.8×10−6 K−1. Our results help to understand the structural origins of the high thermal conductivity and low CTE, and aid in designing ZrW2O8/Cu composites with improved performance.