论文部分内容阅读
以7475-T7351铝合金材料为研究对象,对其在145℃、150℃、155℃和160℃条件下进行了不同应力水平的单向拉伸蠕变持久试验,研究了该材料的蠕变时效行为。考虑材料不进入蠕变第三阶段且获得较大蠕变变形量的要求,确定了最佳时效温度为155℃及其对应的应力范围和时间。在155℃下对蠕变后的试件进行强度校核试验和微观组织观察与分析,结果表明,7475-T7351铝合金在240MPa~300MPa应力作用下进行时效成形,材料蠕变后的力学性能未明显下降,能够满足实际工程应用的强度要求。
Taking 7475-T7351 aluminum alloy as the research object, the uniaxial tensile creep tests with different stress levels at 145 ℃, 150 ℃, 155 ℃ and 160 ℃ were carried out. The creep aging behavior. Considering the material does not enter the third stage of creep and obtain a larger creep deformation, the optimum aging temperature is 155 ℃ and its corresponding stress range and time are determined. At 155 ℃, the strength of the creep specimen was examined and the microstructure was observed and analyzed. The results show that the 7475-T7351 aluminum alloy under the stress of 240MPa ~ 300MPa is aged and the mechanical properties after creep Significantly decreased, to meet the actual engineering requirements of the strength.