Abstract:Three Ti-6Al-4V alloy powders with median diameters of 103, 66 and 44 μm, respectively, were pressed by high-velocity compaction (HVC) technology and then sintered in vacuum. The effects of particle sizes on forming as well as properties of sintered samples were investigated. The results show that fine powders are more difficult to press than coarse powders and its compact density is lower too. But the sintered density of fine powders is obviously higher than that of coarse powders. Compared with the powders with 103 and 66 μm in diameter, the green density with 44 μm diameter powders is lower, which is 85.1% of theoretical density (TD) at an impact energy of 913 J. After sintering at 1300 °C for 2.5 h, the sintered density of the compacts with 44 μm diameter powders is the highest, and reaches 98.2% of TD. Moreover, the sintered sample with 44 μm in diameter has the highest hardness and compressive strength, which are HV 354 and 1265 MPa, respectively.

Key words: Ti-6Al-4V; high-velocity compaction (HVC); green density; sintering