镁合金挤压材的组织演变

Microstructure Evolved of Magnesium Alloy as Extrusion and Anneal

对AZ31B镁合金挤压材加工态和退火态组织进行了研究,结果表明镁合金在热挤压过程中发生了动态再结晶。当挤压比较小以及挤压温度较低时,存在混晶组织和未完全再结晶组织,未再结晶的晶粒为长条状。经过退火,混晶组织中的小晶粒长大,晶粒尺寸变得更均匀,也存在二次再结晶现象。未再结晶组织中的长条状晶粒在300℃退火后,分解成均匀的等轴晶。

The microstructures of AZ31B magnesium alloy as extrusion and anneal were studied. The results showed that the dynamic recrystallization took place during the hot extruding. If the extrusion ratio and the extrusion temperature were lower, there were mixed crystal and un-completed recrystallization as strip in the extruded products. After anneal, the smaller crystal grains in the mixed crystal grew up, so the grain size became uniformity. Moreover, secondary recrystallization was found in this experiment. The strip gain became lots of homogeneous equiaxial crystals that were bigger than recrystallization gains at 300℃ anneal.