AgCuTiZr钎料激光钎焊钛/钢连接机理与接头性能

钛和钢广泛应用于“陆海空天”等领域,由于钛与钢的物理化学性能差异,连接界面常形成大量脆性金属间化合物,限制了其广泛应用。在分析钛/钢异种材料焊接的基础上,采用激光钎焊工艺,利用自行研制的AgCuTiZr钎料进行了钛/钢连接实验研究。结果表明,该活性钎料对基体材料润湿性良好,钎焊层组织致密、表面平整;在结合界面处出现了活性元素的扩散,钎焊层中有多物相共存,界面间实现了化学冶金结合;AgCuTiZr活性钎料激光钎焊层具有较高的硬度,达到基体材料的1.5倍,耐磨性与被连接材料45钢/TA2基本一致,抗拉强度达到595 MPa,实现了两种被连接材料的可靠连接。激光热源的显著优点适合于异种金属材料的钎焊连接。

Connection Mechanism and Properties of Laser Brazed Titanium/steel Joint with AgCuTiZr Brazing Alloy

Titanium and steel are widely used in "land, sea, air and space" fields. Due to the difference in physical and chemical properties of titanium and steel, a large number of brittle intermetallic compounds are often formed at the interface, which limits their wide applications. Based on the analysis of titanium/steel dissimilar material welding, the laser brazing process and self-developed AgCuTiZr brazing alloy is used to carry out an investigation of titanium/steel connection. Experimental results show that this active brazing alloy has good wettability to the matrix material, the microstructure of brazed layer is compact with a smooth surface. The active elements are diffused at the bonding interface, multiple phases coexist in the brazing layer, and chemical metallurgical bonding is realized between interfaces. The brazed layer of active AgCuTiZr alloy possess high hardness, which is 1.5 times that of the base materials. The wear resistance of the AgCuTiZr brazed alloy is basically the same as that of the connecting material 45 steel /TA2, while tensile strength of the brazed layer is 595 MPa, which realized the reliable connection of the two materials. The obvious advantages of laser heat source are suitable for brazing of Heterogeneous metal materials.