TiZrNiCu-B/Ti60润湿性及其与TiBw-TC4钎焊研究（英文）

Wettability of TiZrNiCu-B/Ti60 System and Its Brazing with TiBw-TC4 Composite

采用座滴法在真空下研究了硼含量对TiZrNiCu/Ti60润湿性的影响,且在940℃保温10 min条件下实现了其与TiBw-TC4的钎焊。通过SEM、XRD以及剪切实验研究了界面显微组织及剪切力学性能。结果表明,添加B元素可以与Ti原位合成TiBw,从而细化界面的显微组织。当B质量分数为0.3%时,TiBw-TC4/TiZrNiCu-B/Ti60接头的最大抗剪切强度为177 MPa,比无B的接头强度高65%。然而,过量的B含量使TiZrNiCu-B在Ti60合金基体上产生大量的TiBw,导致润湿性恶化,在钎焊接头形成微孔和未焊合区域,从而使抗剪切强度下降。

The connection between the boron content and the wettability of TiZrNiCu/Ti60 system was studied by a sessile drop method of elevating and maintaining isothermal process under vacuum, and TiBw-TC4 composite was successfully brazed to Ti60 alloy using TiZrNiCu-B filler alloy at a brazing temperature of 940 ℃ for 10 min. The contact angles of TiZrNiCu/Ti60 alloy substrate with the corresponding interfacial microstructure, the interfacial microstructures and shear fractures of brazed joints were studied using SEM, EDS and XRD, and the influence of B content on interfacial microstructure and joining properties was also investigated. The results show that the added B element can react with Ti to in-situ synthesize TiB whiskers(TiBw), which results in a relative refinement of microstructure. And when the content of B is 0.3 wt%, the maximum shear strength of TiBw-TC4/TiZrNiCu-B/Ti60 joint is 177 MPa, which is 65% higher than that of the joints brazed without B. However, the excessive B worsens the wetting behavior of TiZrNiCu-B on Ti60 alloy substrate, resulting in the microvoids and disconnected areas in the brazed joint, and the shear strength decreases inevitably.