摘要
采用铸坯挤压制备具有最终试样二维几何特征的AZ61镁合金预成形坯材,经过一次纵向模压制备了近终成形的拉伸试样,对试样进行了组织和拉伸性能检测。实验结果表明：在挤锻复合成形工艺过程中,材料组织经过变形与再结晶,晶粒尺寸从铸态的121μm细化为挤压态的8-15μm,锻压后进一步细化到2-5μm。经历了挤锻复合成形后,材料的室温抗拉强度、屈服强度、伸长率和硬度分别达到315.2MPa2、27.4MPa和20.5%,比铸态分别提高了42.4%、76%和71%;拉伸失效断口也从铸态的准解理断裂过渡为模压后以韧性断裂为主的特征。
Semi-continuous cast ingots of AZ61 magnesium alloy were extruded into a profile with the similar 2-D geometrical feature to standard tensile specimen. Then, tensile specimens were prepared by net-shape pressing of short section of the profile in a closed die. Mierostructure and mechanical properties of the specimens were characterized by light microscopy and tensile testing. The results indicate that grain size of the alloy are refined from 121μm for as-cast condition to 8 - 15μm for extruded condition and, then, further reduced to 2 - 5μm in its forged condition. The tensile strength, yielding strength and elongation of the as-forged alloy are 315.2MPa, 227.4MPa and 20.5 % , respectively, which are 42.4 % , 76% and 71% ,respectively, higher than that in its as-cast condition. SEM fractography shows that quasi-cleavage fracture is observed for the fracture of the as-cast specimens, while the fracture of the as-forged specimens is mainly characterized by its ductile dimples, indicating the change of the failure from brittle in as-cast condition to ductile in as-forged condition.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2009年第5期154-157,共4页
Transactions of Materials and Heat Treatment
关键词
镁合金
挤锻复合成形
微观组织
力学性能
断裂机制
magnesium alloy
die forging
microstructure
mechanical property
fracture mechanism
