均匀化退火工艺对ZM21镁合金热变形行为的影响

Effect of homogenization annealing process on heat deformation behavior of ZM21 magnesium alloy

将ZM21镁合金分别在Gleeble-1500D上进行热压缩和在500 t卧式挤压机上用工业铸锭进行热挤压试验,研究了均匀化退火工艺对合金变形后组织和热变形行为的影响。结果表明,随360℃均匀化退火时间的延长,ZM21镁合金热压缩变形的峰值应力不断降低;退火时间超过12 h后,峰值应力趋于稳定;同时随退火时间的延长,热压缩变形后的再结晶晶粒尺寸不断增大,但显微组织越来越均匀。均匀化退火对ZM21镁合金挤压态的力学性能影响不大,但可降低挤压时的变形抗力,提高挤压速度,易于挤压成形。

Effect of homogenization annealing process on heat deformation behavior of ZM21 magnesium alloy was investigated, using hot compression test by Gleeble-1500D simulator and billet extruding test with industrial ingot by 500 t horizontal extrusion press. The results show that the peak flow stress of the alloy decreases with the of annealing time at 360 ℃. The peak flow stress becomes steady when the annealing time is more than 12 h. The average recrystallization grain size after compression increases with the annealing time, and the deformation microstructure becomes more uniform. The effect of this annealing on mechanical properties of ZM21 alloy is not significant, while the resistance to the deformation is decreased after homogenization annealing,thus the extrusion speed can be increased and the alloy is easy to be extruded.