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研究了喷射成形挤压7075铝合金在T6、T74和T76时效处理后材料的力学性能变化。结果表明:喷射成形7075铝合金挤压组织具有方向性、晶粒细小,晶内Cu元素含量要低于第二相和晶界;T6单级时效处理后,抗拉强度为714 MPa、屈服强度为672 MPa,伸长率为11.4%,拉伸断口存在沿晶脆性断裂区域。T74和T76双级时效处理能够有效地缩小沿晶脆性断裂区域,双级时效处理后的试样强度低于单级时效,而能够提高合金的伸长率,分别为14.9%和13.1%。
The mechanical properties of the as-extruded 7075 aluminum alloy after aging treatment at T6, T74 and T76 were studied. The results show that the extruded microstructure of 7075 aluminum alloy has the directionality, small grain size and the content of Cu in the grain is lower than that of the second phase and the grain boundary. The T6 single stage aging treatment shows a tensile strength of 714 MPa and a yield strength Of 672 MPa and elongation of 11.4%. Fracture zone along the crystal brittle fracture exists in the tensile fracture. T74 and T76 two-stage aging treatment can effectively reduce the brittle fracture along the crystal region, the strength of the sample after two-stage aging treatment is lower than the single-stage aging, and can improve the elongation of the alloy, respectively, 14.9% and 13.1%.