Be/Al/Be激光焊接接头显微组织分析

铝为过渡材料,运用激光焊接技术实现了铍与铍激光熔焊连接.采用扫描电镜(SEM)、金相显微镜(OM)、微控电子万能试验压力机及微区X射线衍射仪(XRD)对焊接接头的显微组织、剪切断口形貌、力学性能及相结构进行了试验研究.结果表明,Be/Al/Be激光焊接接头为铝与铍形成类似复合材料的双相组织,接头抗剪强度介于铝和铍的抗剪强度之间,随着焊缝组织铍含量增加,接头抗剪强度呈上升趋势、焊接接头断裂形式由塑性断裂向脆性断裂转变、断口形貌由韧窝断口向准解理断口过渡,焊缝中的金属化合物是导致焊缝失效断裂的主要原因.

Microstructure of Be/Al/Be joint by welded laser beam

Application of beryllium alloy was joined with laser welding by taking aluminum as transition material.The mi-crostructure and properties of the welded joint were studied by means of scanning electron microscope (SEM) ,optical micro-scope (OM) ,and X ray diffraction apparatus (XRD) .The re-sults indicated that the microstructure was composed of quasi-composite compound phase formed by beryllium and aluminum.The shear strength lies between aluminum and beryllium.With percent of beryllium in weld zone being more,the size of berylli-um and beryllium particle distribution change,the shear strength of welded joint is higher,the fracture mechanism is transformed form ductile fracture with fractographs of dimples to brittle frac-ture with quasi-cleavage feature.The intermetallic compound in weld zone is the main cause of fracture for Be/Al/Be laser wel-ded joint.