热轧及退火Mg-5Li-1Al板材的组织及力学性能演变

Microstructure and mechanical property development in a hot-rolled and annealed Mg-5Li-1Al alloy sheet

摘要:

Mg-5Li-1Al 合金板材在热轧后分别经150℃和300℃退火30分钟。本文研究了热轧及退火态Mg-5Li-1Al板材的微观组织、力学性能及织构,并且讨论了其塑性变形机制。结果显示,退火态板材显示出了弱的织构和均匀的再结晶组织,其晶粒尺寸大约为15μm。随着退火温度的升高,合金板材的延伸率在逐渐提升,而抗拉强度、屈服强度、屈强比在减小,这些都对合金的成形性能非常有利。经300℃退火30分钟的合金板材表现出最好的力学性能,其原因在于Li元素的添加和退火温度的升高。

Abstract:

Mg-5Li-1Al magnesium alloy sheets processed by hot rolling were annealed at 150℃ and 300℃ for 30 min, respectively. The microstructure, mechanical properties, and texture of rolled and annealed Mg-5Li-1Al alloy sheet were investigated. The plastic deformation mechanism was also discussed. The results show that the annealed sheet possesses weak basal texture and homogenous recrystallized structure with grain size of ~ 15 μm. Increasing annealing temperature results in an increase in tensile elongation and a decrease in tensile strength and yield ratio, which are generally favored for the improvement of sheet formability. The rolled LA51 sheet after annealing at 300℃ exhibits improved mechanical properties due to Li addition and high annealing temperature.