大型铸件用时效态7071铝合金微观组织和力学性能分析  

Microstructure and Mechanical Properties of Aged 7071 Aluminum Alloy for Large Castings

作　　者：陶金仓[1] TAO Jincang(School of Traffic Engineering,Huanhe Science and Technology University,Zhengzhou 454950,China)

机构地区：[1]黄河科技学院交通学院

出　　处：《热加工工艺》2018年第16期221-223,共3页Hot Working Technology

摘　　要：通过微观组织观察、拉伸实验等手段对大型铸件用时效态7071铝合金的组织微观形貌和力学性能进行了观察分析。结果表明：7071铝合金凝固组织包含位于晶界的共晶相以及α（Al）基体相。边缘位置的结晶相数量很少,呈现出等轴分布状态的组织形貌特征;中心部位形成众多网状结构结晶相,晶粒尺寸存在较大差异。时效态7071铝合金中出现再结晶现象。时效态7071铝合金边缘位置的力学性能明显高于中心部位,各轴向上的力学性能明显高于径向。合金断裂形式表现为脆性断裂与韧性断裂共同作用的结果,合金边缘的断口韧窝尺寸在10μm以内,主要表现为韧性断裂特征;中心区域的韧窝数量较少,断口也比较平坦,表现为脆性断裂特征。The microstructure and mechanical properties of aged 7071 aluminum for large castings alloy were observed and analyzed by means of observation and mechanical tensile experiment. The results show that the solidification structure of7071 aluminum alloy is composed of eutectic phase at grain boundary and α（Al） matrix. The number of crystal phases in the marginal position is very small, and the morphology presents is oaxial distribution. There are many reticular crystal phases in the center, and the grain size is different. The recrystallization occurs in the aged 7071 aluminum alloy. The mechanical properties of the edge position of 7071 aluminum alloy are obviously higher than that of the center, and the mechanical properties in axial direction are obviously higher than that in radial direction. The fracture form of the alloy is joint of brittle fracture and ductile fracture. The fracture dimple size of the alloy edge is within 10 μm, which shows ductile fracture characteristics. The number of dimples in the central area is small, and the fracture is relatively flat, which is characterized by brittle fracture.

关 键 词：7071铝合金 时效处理 组织演变 力学性能 

分 类 号：TG156.92[金属学及工艺—热处理] TG166.3[金属学及工艺—金属学]