搅拌摩擦焊接头抗拉强度无损表征

Non-destructive evaluation of FSW tensile property

材料的弹性模量、显微结构及相应的力学性能可用超声学来表征.对力学性能起决定性作用的显微结构与超声衰减有明显的相关性.采用接收到的斜入射透射波能量变化来表征超声波在搅拌摩擦焊接头(FSW)不同组织中的衰减,从超声C扫描图像中提取特征,计算了接头拉伸时的净工作面积.结果表明,检测图像特征与接头实测拉伸性能之间具有良好的相关性,证明了用超声波无损表征的方法预测FSW接头抗拉强度是可行的.

Elastic module,microstructure of materials and corresponding mechanical properties can be characterized by ultrasonic methods,especially,the microstructure,a crucial factor of mechanical properties,correlating with ultrasonic attenuation obviously.In the present research,a focusing angle beam immersion system was adopted to receive the transmission wave which represents to penetrated attenuation caused by the different microstructure of friction stir welding(FSW)joints,and the feature of FSW joints had been extracted from C-scan images for non-destructive evaluation of the tensile properties of welds.A desirable correlation between the calculating and testing results of ultimate tensile strength was presented,which indicates the feasibility of predicting mechanical properties of FSW joints by ultrasonic methods.