硬铝约束对纯铝韧脆转变的影响

Effect of LY12 Alloy Constraint on the Ductile to Brittle Transition of Al Interlayer

本文通过四点弯曲试验以及数值模拟方法对爆炸焊接的LY12/Al/LY12层合材料中纯铝中间层在不同界面强度错配比条件下裂端应力场及韧脆转变行为进行了研究。结果表明:在双侧硬铝约束下,界面强度错配比增加对裂端应力三轴度及其分布具有显著影响,裂端前沿应力三轴度的提高对中间纯铝层韧脆转变起主导作用,在一定应力三轴度及最大主拉应力条件下,裂端前沿将发生脆性解理启裂。

Four-point bend test and numerical simulation method were used to investigate the crack tip stress and strain field and ductile to brittle transition behavior of pure Al interlayer, which was constrained by LY12 alloy at both sides through explosive bond method, under different strength mismatch ratio after heat treatment at different temperatures. The results show that the increase of strength mismatch ratio at interlaces has an obvious effect on the triaxial tensile stress and its distribution, and the increase of stress triaxiality has a dominant role in the ductile to brittle transition of Al interlayer. Cleavage will initiate at crack-tip of the Al interlayer under critieal stress triaxiality and maximum tensile stress.