激光热处理对T74态7B04铝合金板材性能的影响

Effect of laser heat treatment on properties of T74 state 7B04 aluminum alloy sheet

为了探究T74态7B04铝合金经过激光热处理后的性能变化,对1.5 mm厚T74态7B04铝合金板材进行了不同温度下的激光热处理,并对激光热处理后的T74态7B04铝合金试件进行了单向拉伸试验和断口形貌观测。试验结果表明:与原始T74态7B04铝合金相比,激光热处理后T74态7B04铝合金断后伸长率显著提高且强度下降较小。当激光热处理功率为884 W,对应热处理温度为540℃时,T74态7B04铝合金试件的断后伸长率提高了110.91%,抗拉强度和屈服强度分别下降了11.48%和5.9%;断口观测结果表明激光热处理后的材料韧窝增多且加深,且激光热处理前后均属于韧性断裂,与单向拉伸试验结果一致,说明激光热处理在有效增强T74态7B04铝合金的塑性的同时,使得合金的强度有所保持。

To explore the propeties change of T74 state 7B04 aluminum alloy after laser heat treatment,the T74 state 7B04 aluminum alloy plate with thickness of 1.5 mm was subjected to laser heat treatment at different temperatures,and uniaxial tensile test and fracture morphology observation of T74 state 7B04 aluminum alloy specimens after laser heat treatment were carried out.The tests results show that compared with the original T74 state 7B04 aluminum alloy,after laser heat treatment,the elongation after fracture of T74 state 7B04 aluminum alloy increases significantly and the strength decreases less.When the laser heat treatment power is 884 W and the corresponding heat treatment temperature is 540℃,the elongation after fracture of T74 state 7B04 aluminum alloy increases by 110.91%,and the tensile strength and yield strength decrease by 11.48%and 5.9%,respectively.The results of fracture observation show that the dimples of the material after laser heat treatment increase and deepen,and belong to ductile fractures before and after laser heat treatment,which are consistent with the results of uniaxial tensile test,indicating that laser heat treatment can effectively enhance the plasticity of T747B04 aluminum alloy and maintain the strength of the alloy.