蠕变时效工艺参数对7475铝合金力学性能的影响

Effect of creep age forming parameters on mechanical properties of 7475 aluminum alloy

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。

To study the creepage properties of 7475-T7351 aluminum alloy, the uniaxial creep tests were conducted under different stress conditions at 145 ℃, 150 ℃, 155℃ and 160℃. To obtain much strain deformation while avoiding the material going into the third stage of the creep-age, the best age temperature is 155℃and the range of creep time under different stress levels are also acquired. The strength verification tests and the microstructure observation tests of the specimens after creep tests under 155℃ prove that the material＇s mechanical properties after creep tests under stress levels between 240MPa and 300MPa does not decline dramatically, which means that the material can meet the strength demands of practical engineering applications for creepage forming.