| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1603907 | International Journal of Refractory Metals and Hard Materials | 2011 | 8 Pages |
Ultra-fine tungsten powder with a BET particle size of 210 nm was synthesized by sol spray drying, calcination and subsequent hydrogen reduction process. Then this powder was treated by ball-milling, the characteristic changes of this powder before and after milling were investigated. Then the sintering densification behavior of these powders with different ball-milling time (0 h, 5 h, 10 h) were also studied. The results show that ball-milling treatment greatly activates the sintering process of ultra-fine tungsten powder. The relative density of the powder ball-milled for 10 h could reach 97.3% of theoretical density (TD) when sintered at 1900 °C for 2 h, which is 600 °C lower than the required temperature of the traditional micro-scaled powder sintered for the same density. At the same time, ball-milling treatment could substantially reduce the onset temperature of sintering as well as recrystallization, and bulk tungsten materials with more uniform and finer microstructure and much better mechanical properties (hardness) could be obtained.
► Sol spray drying method was used to prepare ultra-fine tungsten powder. ► Ball milling was utilized to improve the sinterability of ultra-fine tungsten powder. ► Ball milling reduces sintering and recrystallization onset temperature of ultra-fine tungsten powder. ► Ultra-fine tungsten powder ball milled for 10 h can be sintered to 97.3%TD at 1900 °C. ► The microstructure evolution process during sintering was systematically observed.
