Effect of ZrC particle size on microstructure and room temperature mechanical properties of ZrCp/W composites

Tungsten composite reinforced by 20 vol.% ZrC particles with three different mean particle size (1.25, 1.71 and 5.78 μm) were prepared by hot-pressing at 2200 °C, 25 MPa for 1 h. The effect of ZrC particle size on microstructure and room temperature mechanical properties is investigated by examining the ZrC particle distribution, pore in the particle clusters, and composition of the ZrC/W interface and strength of the composites. The results show that a small amount of tiny pores existed in the ZrC particle clusters with a mean size of 1.25 μm, and the larger pores was observed when the mean size was 5.78 μm. (Zr,W)C solid solution was found at the ZrC/W interface, and W2C phase formed when the ZrC particle size was less than about 1.71 μm. The flexural strength of the ZrCp/W composite is deteriorated by the ZrC particle clusters and the defects within the ZrC particles. The highest strength of 1210 MPa was tested on the composite containing 1.71 μm ZrC particles.