超声冲击处理2A12铝合金焊缝表层微观组织结构变化
朱有利;李占明;何嘉武;汪勇
【期刊名称】《材料工程》 【年(卷),期】2009(000)007
【摘要】2A12 aluminum alloy welded joint was strengthened by Ultrasonic Impact Treatment (UIT). The microstructure characterization of the welded bead surface layer with and without UIT was studied by SEM observation and X-Ray Diffraction (XRD) analysis. Results show that the metallurgical structure of the near surface material of the weld zone was densified due to ultrasonic impact treatment. The depth of plastic deformation extended up to about 300μm from the surface. The grain refinement behavior was obvious. XRD analysis show that the diffraction peaks after UIT was broadened significantly, which was related to grain refinement and lattice distortions. Quantitative estimation of the grain size and of the lattice distortions after UIT was evaluated by Scherrer equation and Williamson formula based on the peak broadening. Results show that the average grain size after UIT is about 123nm and the average micro-strain value is about 0.134%. At last, the mechanisms of grain refinement were discussed.%采用超声冲击工艺对母材为2A12铝合金焊接接头进行了焊后处理.利用扫描电镜、X射线衍射分析了超声冲击处理前后焊缝表面层的微观组织结构特征.结果表明,超声冲击处理可以在焊缝表面形成约为300μm的致密塑性变形层,晶粒明显细化.对X射线衍射峰的观察分析表
超声冲击处理2A12铝合金焊缝表层微观组织结构变化
