Structure and Properties of W-Cu/AlN Composites Prepared via a Hot Press-Sintering Method

W-30wt% Cu nano-crystalline powder was prepared by high-energy ball-milling, and then different mass fractions of AlN nanoparticles were added to the powder via the ball-milling. Finally W-30Cu/x% AlN composites were obtained by hot press-sintering process. The microstructures, the physical and mechanical properties of as-sintered composite samples were studied. The results indicate that the W-30Cu/x% AlN composites possess denser and more uniform microstructure. Moreover, the degree of refinement of W particles and the hardness of the composites increase with the addition of AlN, but the bending strength decreases with increasing of AlN nanoparticles due to the nanoparticles excessive distribution on the grain boundaries of the matrix. It is beneficial to increase thermal conductivity of W-Cu composites, when the content of AlN nanoparticles is ≤1%. Resistivity of the composites increases with increasing the amount of AlN nanoparticles, but the conductivity of the composites declines.