有限元分析宽厚比对镁合金变通道挤压的影响

Effect of Flakiness Ratio on Change Channel Angular Extrusion of Magnesium Alloy Based on Finite Element Software

采用有限元分析软件,对250℃下AZ31镁合金变通道角挤压进行数值模拟分析,研究宽厚比k对成型过程中的挤压载荷、等效应力、等效应变和应变均匀性的影响。结果表明：宽厚比k对AZ31镁合金挤压成型过程中的挤压载荷、等效应力、等效应变和应变均匀性影响明显。k由4增长至10时,挤压载荷由1.1×10~6N增至5.5×10~6 N。k小于8时,试样的应力等效最大值约为270 MPa;当k为8时,在转角剪切区应变高达2.3,心部和表层的应变差值小于0.5,剪切区累积了大量的应变且应变均匀性高,易诱发动态再结晶和晶粒碎裂,细化晶粒,增强AZ31镁合金的强韧性能。

Flexible angle extrusion of AZ31 magnesium alloy at the temperature of 250 ℃ was numerically simulated and analyzed using finite element analysis software to study the influence of flakiness ratio on extrusion load,equivalent stress,equivalent strain and strain uniformity in the process of forming.The results show that the influence of flakiness ratio k on extrusion load,equivalent stress,equivalent strain and strain uniformity are obvious in the extrusion process of AZ31 magnesium alloy.The extrusion load is increased by three times from 1.1×10~6N to 5.5×10~6N with the growth of k from 4 to 10.When k≤8,the maximum stress of the specimen is 270 MPa.But when k=8,the maximum strain is up to2.3 in the angle of the specimen,the strain difference between core and surface of the specimen is less than 0.5.Due to shear zone accumulate a lot of strain,and strain uniformity is high,it is easily induced dynamic recrystallization and grain fragmentation to refine the grain size and enhance the strength and toughness of AZ31 magnesium alloy.