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采用拉伸实验、光学显微镜(OM)、扫描电镜(SEM)等研究了3种不同时效工艺对挤压态喷射成形7055铝合金显微组织和力学性能的影响。结果表明:铝合金的晶粒细小,组织均具有方向性;Cu元素在晶界和第二相中的含量都比晶内的高;但经T6峰值时效处理后,合金出现部分沿晶脆性断裂区域,其抗拉强度达到705 MPa,断裂伸长率达到11.5%;经T76过时效处理后,合金沿晶脆性断裂区域减小,合金的抗拉强度达到659 MPa,伸长率为10.9%;经T74过时效处理后,韧性进一步改善,其抗拉强度为640 MPa,伸长率为15.3%。
The effects of three different aging processes on the microstructures and mechanical properties of 7055 aluminum alloy by extrusion injection molding were studied by means of tensile test, optical microscope (OM) and scanning electron microscope (SEM). The results show that the grain size of the aluminum alloy is fine and the microstructure is directional. The content of Cu in the grain boundary and the second phase is higher than that in the crystal phase. However, after T6 peak aging treatment, The tensile strength of the alloy reached 705 MPa and the elongation at break reached 11.5%. After aging treatment with T76, the brittle fracture zone of the alloy decreased. The tensile strength of the alloy reached 659 MPa and the elongation was 10.9%. T74 after aging treatment, the toughness to further improve the tensile strength of 640 MPa, elongation of 15.3%.