焊接能量对Mg/Ti超声波焊接接头微观组织与力学性能的影响

Effect of welding energy on microstructure and mechanical properties of the Mg/Ti joints welded by ultrasonic spot welding

摘要:

采用超声波焊接技术对Mg/Ti异种金属进行了焊接,研究了不同焊接能量对接头界面峰值温度、界面形貌、界面原子扩散程度以及力学性能的影响规律。研究发现：Mg/Ti超声波焊接接头整体界面较平直,局部界面有较小起伏,没有发现裂纹、未熔合等缺陷,也没有看到明显的反应层；随着焊接能量的增大,界面峰值温度升高,原子扩散层厚度增大,连接区面积逐渐增大,接头力学性能得到提高,而能量达到2000J时镁侧母材出现裂纹；接头断裂模式分为界面断裂和纽扣断裂,界面断裂时断裂发生在镁侧扩散层区域和镁侧非扩散层区域。扫描电子显微镜和X射线衍射仪分析表明,Mg/Ti连接界面区域没有明显的金属间化合物生成。

Abstract:

Mg/Ti dissimilar metals were welded by ultrasonic welding. The effects of different welding energy on the interfacial peak temperature, interfacial morphology, interfacial atom diffusion degree and mechanical properties of the joint were investigated. It is shown that the overall interface of Mg/Ti is relatively straight during the welding process, the local interface has small fluctuations, no cracks, lack of fusion and other defects are found, and no obvious reaction layer is observed. The interfacial peak temperature ,the thickness of the atomic diffusion layer , the connection zone and mechanical properties of the joint increase with the increase of welding energy. When the energy reaches 2000J, the magnesium side base material shows welding cracks. The joint fracture mode is divided into interface fracture and button fracture. The fracture location occurs at the magnesium side diffusion layer area and the magnesium side non-diffusion layer area. Scanning electron microscopy and X-ray diffractometry analysis showed that there was no obvious intermetallic formation in the Mg/Ti interface region.