【摘要】 通过硬度、室温拉伸测试和断口形貌观察实验，并结合金相和扫描电镜结果分析，研究了7、10、16的热挤压比对喷射成形7055铝合金微观组织及力学性能的影响。结果表明，经均匀化热处理后，粗大的第二相大部分溶解，仅残余少量的富Cu、Fe粒子。随着热挤压比从7增大到10,T6态合金的硬度从205.7 HV增加到208.1 HV，屈服强度和抗拉强度分别从677.1、728.4 MPa增大至687.3、735.6 MPa。挤压比进一步增大时，硬度增加到212.95 HV，屈服强度和抗拉强度分别增加到700.5、747.2 MPa，伸长率从7.9%略微减小到6.7%，沿晶断裂趋势更为明显。随着挤压比增大，合金中孔隙的面积分数和尺寸显著减小，晶粒尺寸略有减小且亚结构密度增加，导致合金的硬度和强度增大，更高的晶界密度沿晶断裂倾向更明显。更多还原

【Abstract】 The impact of different hot extrusion ratios on the microstructure and mechanical properties of 7055 aluminum alloy produced through spray forming was investigated by hardness testing, tensile tests, and fracture morphology observations, along with metallographic and scanning electron microscopy characterizations. The results show that after the homogenization heat treatment, the coarse second phase is mostly dissolved, and only a small amount of Cu-and Fe-rich particles remain. With the increase of the hot extrusion ratio from 7 to 10, the hardness of the T6 state alloy increases from 205.7 HV to 208.1 HV, and the yield strength and tensile strength increases from 677.1 MPa and 728.4 MPa to 687.3 MPa and 735.6 MPa, respectively. When the extrusion ratio is further increased, the hardness increases to 212.95HV, and the yield strength and tensile strength increase to 700.5 MPa and 747.2 MPa, respectively. The elongation slightly decreases from 7.9%to 6.7%. The alloy exhibits a significant reduction in pore area fraction and size with increasing extrusion ratio, along with a slight decrease in grain size and an increase in substructure density. These factors contributed to the enhanced hardness and strength of the alloy. Additionally, the higher grain boundary density is identified as the reason for the more noticeable fracture tendency along the grains.更多还原