超轻Mg-Li-Zn系变形镁合金冷轧及热处理后的显微组织和性能

Microstructrues and Properties of Superlight Mg-Li-Zn Wrought Alloys in Cold-rolling and Annealing States

研究了超轻变形镁合金Mg-5%～22%Li-2%Zn的冷轧性能、热处理特性以及机械性能.合金的密度为1.209～1.617g/cm3.在室温条件下β相合金(16%和22%Li)具有非常良好的延展性,压下极限可达到90%以上.研究了Mg-Li-Zn系变形镁合金铸锭经不同温度、不同时间均匀化退火后的组织性能.对均匀化后的合金锭进行了冷轧,轧后板材在不同温度下进行退火,研究了其再结晶行为及组织性能.结果表明,Mg-9%Li-2%Zn-2%Ca合金在573K温度下均匀化退火12h后合金铸锭组织均匀,有利于冷轧开坯变形;而Mg-9%Li-2%Zn合金523K温度下均匀化退火24h后组织较好.冷轧合金板材在573K温度退火1h可发生完全再结晶,生成细小均匀的等轴晶组织.

Cold-rolling workability, heat treatment characteristics and mechanical properties of Mg-5%-22%Li-2%Zn wrought alloys were studied. Density of the studied alloys is in the range between 1.209 and 1.617 g/cm^3. The limit of reduction for cold rolling of the β phase alloys with 16% and 22% Li exceeds 90% at room temperature. The properties and microstructures of Mg-Li-Zn system alloys were studied. The alloys were coldly rolled, then annealed at different temperatures. Recrystallization behaviors of the alloys were investigated through microstructure observing and hardness measuring. The results show that the cast billets are suitable for rolling after homogenization at 573 K for 12 h for Mg-9%Li-2%Zn-2%Ca alloy and at 523 K for 24 h for Mg-16%Li-2%Zn alloy. The rolled plates are completely recrystallized by annealing at 573 K for 1 h. It is beneficial to the next cold-rolling.