Effects of Powder Pretreatment Process on Oxygen Content and Grain Size of Al-Ti Target

Al-Ti mixed powder with low oxygen content was prepared by pretreatment process,including ball-milling process, centrifugal separation process and mixture process, and Al-Ti target was prepared by hot isostatic pressing process.The oxygen content and grain size of Al-Ti target were characterized by oxygen-nitrogen analyzer and scanning electron microscope. The results show that, along with the increase of the rotating speed of the ball-milling raw material powder in the pretreatment process of ball-milling, centrifugal separation and powder mixed, both the oxygen content in the Al-Ti target and the grain size of the aluminum matrix decrease gradually. This is due to the fact that after powder pretreatment, the brittle oxidized film on the surface of the raw material powder is gradually fractured, peeled off and eventually separated out, and the strain accumulated in aluminum particles during the milling of the raw material powder promotes the recrystallization of the aluminum matrix phase during the hot isostatic pressing. When the milling speed is 300 r/min, the oxygen content of Al-Ti target is reduced to 0.12%, and the average grain size of aluminum matrix reduces to 2 μm.