【摘要】 通过模拟空间热循环试验,研究了热循环因素对5A06铝合金焊接接头断裂机理的影响。结果表明,热循环及外加载荷环境会造成5A06铝合金焊接接头断裂机理的改变,会在焊接接头的热影响区处形成更多的损伤。这是由于焊接热影响区中聚集、析出的第二相粒子的热膨胀系数与铝合金母材相差很大,热循环及外加载荷造成了基体与第二相之间的脱离,导致接头性能劣化和断裂机理的改变。更多还原

【Abstract】 Based on simulated aerospace thermal cycling test,the fracture mechanism of 5A06 Al alloy welded joints was studied under the condition of external load and thermal cyclic load.The results show that the thermal cycle with external load can cause the change of fracture mechanism.It also can induce more severe damage in the welded joint than in the base 5A06 aluminium alloy.This is because of the big difference between the base aluminum alloy and the inclusions in the weld as well as the second phase particles in the heat affected zone.The thermal cycle with external load can induce the debonding between the base alloy and second phase particles,which results in the performance deterioration and fracture mechanism change of the welded joint.更多还原