论文部分内容阅读
采用光纤激光焊对厚度为2 mm的细晶Mg-5Zn-1Mn-0.6Sn镁合金板材进行焊接,研究焊接接头的成形特征、显微组织和半熔化区的液化行为。研究结果表明,随着焊接功率的降低及焊接速度的增大,焊接接头的宽度和深度减小;此外,当焊接速度过快时,焊缝中会出现气孔。在半熔化区中主要存在两种液化现象:一种是由基体熔化及偏析诱导液化导致的沿晶界的液化网络,另一种为由晶界上残余第二相液化导致形成的液化熔池现象。在本研究中,主要的液化机制为基体的熔化及偏析诱导液化。
The fine grain Mg-5Zn-1Mn-0.6Sn magnesium alloy sheet with a thickness of 2 mm was welded by fiber laser welding to study the forming characteristics, microstructure and liquefaction behavior of the welded joints. The results show that with the decrease of welding power and the increase of welding speed, the width and depth of welded joints decrease. In addition, when the welding speed is too fast, the weld pores will appear. There are mainly two types of liquefaction phenomenon in the semi-melting zone: one is the liquefaction network along the grain boundary caused by the liquefaction induced by the matrix melting and segregation, and the other is the liquefied melt pool formed by the residual second phase liquefaction on the grain boundary phenomenon. In this study, the main mechanism of liquefaction is the matrix melting and segregation induced liquefaction.