Effect of mechanical alloying on selective laser sintering of WC-9Co powder

It has been generally believed that the ductility of tungsten can be increased by decreasing grain size to ultrafine levels (~100nm). Pure ultrafine grain tungsten powders of various average particle sizes (2.0, 0.7, and 0.16)(mu)m) were consolidated using the rapid consolidation technique, plasma pressure compaction (P2C), to minimise grain growth. Preliminary results indicate that tungsten powders can be consolidated to high density without abnormal grain growth at 2000°C and 50 MPa with less than 3 min of isothermal holding time in the P2C process. The densities of consolidated specimens were measured using Archimedesʹ method, and the microstructure was analysed using SEM. The mechanical behaviour of the consolidated specimens was investigated using the compression Kolsky bar. Dynamic compression properties were examined to determine the effect of grain size, grain structure, and density on yield stress at various strain rates.