Using the titanium hydride powder directly as the starting material to manufacture the titanium and titanium alloy is a method that goes beyond the traditional powder metallurgy technology. Dehydrogenation and shrinkage of TiH2 powders with different particle sizes are studied using thermogravimetric and dilatometric techniques. The process factors such as the sintering temperature,, the sintering time, the heating rate,, the compaction density,, the compaction methods, and the alloy system, would affect the sintering densification of TiH2 powders and TiH2-Al-V alloy powder. It is shown that the dehydrogenation temperature of the starting and ending of the ball milling TiH2 is lower than that of the coarse TiH2 powders, the finer the TiH2 powder, the lower the temperature. The densification of TiH2 powders is easy because of the combination of dehydrogenation and shrinkage of α-Ti in one process, which creates the fresh dehydrided titanium uniform during sintering, thus leads to rapid densification and very high sintereing relative density, higher than 99%. In contrast, it is difficult to achieve a full densification of TiH2-Al-V alloy powder during sintering, which requires dissolution of alloy elements during sintering above its beta transformation temperature. The sintered microstructure of Ti-6Al-4V shows the typical lamellar shaped α+β characteristics,with a uniform alloy element distribution.
ZHANG Jiamin;YI Jianhong;LEI Ting;FANG Zhigang;GAN Guoyou;YAN Jikang;DU Jinghong;FANG Shuming;WANG Hongtao
. Dehydrogenation and Sintering Process of Titanium Hydride for Manufacture Titanium and Titanium Alloy[J]. Science & Technology Review, 2012
, 30(1)
: 65
-68
.
DOI: 10.3981/j.issn.1000-7857.2012.01.012