FABRICATION OF POROUS Ti- AND W-COMPACTS BY ELECTRO-DISCHARGE-SINTERING PROCESS

A single pulse of 0.57–1.1 kJ/0.3 g-spherical Ti -powder in size range of 30–70 μm, using a constant 450 μF capacitor, was applied to produce fully porous Ti - and W -compacts by electro-discharge sintering. Microstructure examination and hardness measurement of the porous Ti -compacts revealed that more stable necks formed with increasing electrical input energy up to 1.1 kJ. On the contrary, W -compacts using rectangular W -powders in size range of 5–15 μm are composed of solid region with micropore and porous layer with weak particle bonding indicating heterogeneous structure. These results suggest that the powder morphology plays a crucial role to control the porous microstructure.