喷射成形7055铝合金型材的力学性能

Mechanical Properties of Extrusions of Spray Formed 7055 Al Alloy

研究了工业级规格喷射成形7055铝合金经反向挤压和T76热处理后的金相显微组织、力学性能和断裂机理。结合OM、SEM、EDS、XRD和力学性能测试等分析方法,研究了该工业级规格的7055铝合金的初始组织、挤压工艺及热处理制度对显微组织和力学性能的影响。结果表明:喷射成形7055铝合金锭坯的晶粒呈等轴状,尺寸均匀,大小主要分布在20-40μm,没有明显宏观偏析。喷射成形锭坯经反向挤压和T76热处理后变形晶粒发生部分再结晶,组织致密;工业级规格产品T76态纵向抗拉强度可达680 MPa,延伸率为10%。

The effect of indirect extrusion process and T76 heat treatment on microstructure evolution and mechanical properties of the spray formed 7055 alloy was investigated by means of optical microscopy, SEM, EDS and XRD as well as mechanical testing. The results show that the as-sprayed billet has an equiaxed and homogeneous structure with grain sizes of 20- 40μm and without macro- segregation. After indirect extrusion and T76 heat treatment, the billets were fully densified with a certain amount of recrystallized grains. The ultimate tensile strength of the alloy after T76 heat treatment reaches680 MPa with 10% elongation.