Cu含量对Al-Mn合金板材激光焊接热影响区晶界液化的影响

Effect of Cu Content on Grain Boundary Liquefaction in Laser Welding Heat Affect Zone of Al-Mn Alloy Sheet

通过高温热处理试验、金相观察等,研究了Cu含量对Al-Mn合金板材激光焊接热影响区晶界液化的影响。结果表明,增加Cu的含量,Al-Mn合金板材在受热时易于出现晶界液化;试验条件下,Cu含量达0.45%时,出现显著的晶界液化现象;微观组织观察表明,随着Cu含量的增加,Al-Mn合金板材在受热时晶界上将形成富Cu的低熔点相液膜,使得易于产生液化裂纹。

This paper presents the study of the effect of Cu content on grain boundary liquefaction in laser welding heat affect zone of Al-Mn alloy sheet via high temperature heat treatment test and metallographic observation. The results show that it is prone to appear the grain boundary liquefaction for Al-Mn alloy sheet after heat with the increase of Cu content. Under test conditions,there is obvious grain boundary liquefaction when Cu content reached 0. 45%. Microstructure observations indicates that it is easier to form liquid film of Cu-bearing low melting phases at grain boundary with the increase of Cu content,therefore,liquefaction cracks are easily produced.