预热温度对铝合金搭接激光焊焊缝成形及组织的影响  

Effect of preheating temperature on weld shaping and microstructure for laser lap welding of aluminum alloy

作　　者：李永强[1] 赵熹华[1] 赵贺[2] 李民[1] 张伟华[1] 

机构地区：[1]吉林大学材料科学与工程学院,长春130022 [2]哈尔滨工业大学现代焊接生产技术国家重点实验室,哈尔滨150001

出　　处：《吉林大学学报（工学版）》2008年第5期1065-1068,共4页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(50575091)

摘　　要：采用Nd:YAG激光器和1.4 mm厚的5A03H24铝合金板材,在不同预热温度下用相同的激光焊参数进行了搭接激光焊试验。结果表明:焊缝的熔深、熔宽随温度的升高而增大,并在T≥250℃时增大显著;焊缝成形和焊接过程稳定性在T≤250℃时随温度的升高而变好;焊缝组织随温度的升高而粗化,但T≤200℃时粗化不明显;焊缝、热影响区和母材的显微硬度随温度的升高而下降,但T≤100℃时焊缝的显微硬度下降不明显,T≤200℃时热影响区的显微硬度下降不明显,T≤300℃时母材的显微硬度下降不明显。Laser lap welding experiments of aluminum alloy 5A03H24 of 1.4 mm thickness were carried out using Nd.. YAG laser at different preheating temperature with the same welding parameters. The results show that the width and the penetration of the welds increase with increasing the preheating temperature,this phenomenon become more evident when the temperature is higher than 250 ℃. The processing stability and weld shaping are improved as the temperature is increased below the 250 ℃, the microstructures of the welds become coarse but not evident when as the temperature is less than 200 ℃, as the preheating temperature is increased, the microhardness in the different regions decreased to different extents, qutie little in the weld, HAZ and base material as the temperature is lower than 100℃, 200 ℃ and 300 ℃ ,respectively.

关 键 词：材料合成与加工工艺 激光焊接 预热 搭焊 铝合金 焊缝成形 显微组织 

分 类 号：TG456.7[金属学及工艺—焊接]