论文部分内容阅读
对AZ61镁合金进行了钨极氩弧焊走焊,然后在焊缝与母材的边界上进行钨极氩弧点焊,同时在点焊中心利用球形凸模加载使其变形。利用扫描电镜和能谱仪分析了试样裂缝分布规律、裂缝附近和晶界析出物的元素偏析情况。研究表明:与三次走焊试样相比,一次走焊试样的焊缝热影响区开裂较严重,具有沿晶式破坏特征,属于热裂缝;一次走焊试样裂缝附近出现了铝和锌元素的偏析现象,而三次走焊试样表面却出现了铝元素减少;点焊热影响区晶界析出物为低熔点共晶物γ-Mg17Al12。
The AZ61 magnesium alloy was subjected to TIG welding and then to TIG welding on the boundary between the weld and the parent metal and deformation was performed by using a spherical punch in the spot welding center. The crack distribution, the segregation of the precipitates near the cracks and the grain boundaries were analyzed by SEM and EDS. The results show that compared with the three samples, the cracking of heat-affected zone in one pass is more severe, with the characteristics of intergranular failure, which belongs to the hot crack. The aluminum and zinc Elemental segregation phenomenon, and three times to go welding the sample surface appears to reduce the aluminum; spot heat affected zone grain boundary precipitates for the low melting point eutectic γ-Mg17Al12.