Preparation for WC-FeAl Hard Metal by Vacuum Sintering

Abstract

The preparation for WC-FeAl hard metal by vacuum sintering was investigated. The mixture of WC and FeAl (Fe-40at%Al) powders which composition was WC-25vol.%FeAl were treated by wet-milling for 70 hr. The average particle size of the powder mixture decreased from 4.2 μm to 1.1 μm by wet milling. The powder mixtures before and after wet milling were press-molded into the test-piece and sintered in vacuum of 10^-2∼10^-1 Pa order at various temperature for 1 hr. The densities, microstructures and mechanical properties of the obtained sintered compacts were investigated. When powder mixture after wet milling was used, the compact sintered at 1450°C had the good relative density of 98.0 %, Vickers hardness of 1350 HV and transverse rapture strength of 2.0 GPa. By the EPMA observation, it was cleared that homogenity of microstructure enhanced by wet milling.