半固态镁合金制浆工艺与组织特征

Preparation Technology of Semi-solid AZ91D Alloy Slurry and Its Structure Feature

采用自行设计制造的半固态镁合金机械搅拌装置,制备镁合金半固态浆料,研究了搅拌工艺参数对半固态镁合金组织的影响。结果表明,搅拌速率、静置时间和搅拌温度对半固态组织影响很大,搅拌速率在1 000 r/min时,静置时间为5～10 min,搅拌温度在560～580℃时,获得的组织均匀细小。搅拌速率过大,晶粒尺寸反而有所增大;静置时间影响半固态组织中固相晶粒的长大;搅拌温度影响固相率,从而也影响到固相晶粒的圆整度。

The semi-solid metal slurry of AZ91D magnesium alloy was prepared by a self-made mechanical stirring device.The effect of technological parameters on the microstructure of semi-solid magnesium alloy was studied.The results show that the uniform and fine microstructures can be obtained while stirring rate is 1 000 r/min,stay time is around 5～10 mins,and temperature is hold at 560 ℃～580 ℃.If the stirring rate is too high,stay time lasts too long,the grain size will increase.The stirring temperature affects the ratio of solid phase,thus affects the roundness of grains.