Ce对热轧AZ31镁合金动态再结晶及织构的影响

EFFECT OF Ce ON THE DYNAMIC RECRYSTALLIZATION AND TEXTURE OF AZ31 MAGNESIUM ALLOY DURING HOT ROLLING

研究了Ce对热轧AZ31合金的动态再结晶过程及织构的影响.结果表明:加入Ce后抑制了AZ31合金中孪生动态再结晶(TDRX)的发生,还加速了合金动态再结晶进程,同时显著弱化了基面织构.EBSD分析表明,在AZ31 1.0Ce(质量分数,%)合金中,除(0001)基面织构外,还出现了介于(0001)基面和(1010)柱面的取向强度峰值,说明Ce的加入激活了变形时的非基面滑移系.Ce的加入并没有使合金的轴比值降低,相反还略有升高,说明非基面滑移的激活并非晶格结构的变化所致. Ce的加入可能改变了Mg原子之间的结合态以及增加了合金的层错能,使得非基面滑移系被激活,从而导致基面织构弱化.

The effects of Ce on the dynamic recrystallization （DRX） and texture of AZ31 magnesium alloy during hot rolling were investigated. It was found that the twin DRX is suppressed in AZ31 1.0Ce alloy, the DRX is accelerated and the basal texture is weakened significantly by adding l%Ce （mass fraction） into AZ31 alloy. The EBSD results show that besides （0001） basal texture, there is an apparent peak intensity between （0001） and （1010） in AZ31 1.0Ce alloy, which means the activation of non basal slip system. The addition of Ce does not result in a decrease of c/a ratio. On the contrary, the c/a ratio is slightly increased by adding of l%Ce. It indicates that the activation of non-basal slip system does not stem from the change of crystal structure. The activation of non-basal slip and the corresponding basal texture weakening are attributed to the change in atomic binding states and stacking fault energy.