旁路分流电弧钎焊钛/钢异种金属接头特性分析

Characteristic of titanium/steel dissimilar metals joint brazed by bypass-current arc welding

关键词:  钛/钢异种金属  旁路分流电弧钎焊  成分分析  抗拉强度  硬度

Key words:  Ti/steel dissimilar metal  bypass-current arc brazing  element analysis  tensile strength  hardness

摘要:

以旁路分流电弧焊方法为技术手段，以S211铜合金为填充钎料，进行钛/钢异种金属电弧钎焊工艺试验. 利用光学显微镜、扫描电镜、万能拉伸试验机等，对钎焊接头的宏观及微观组织、元素分布、抗拉强度进行分析，并利用显微硬度仪分析钎焊接头硬度的变化趋势. 结果表明，采用该方法可获得成形良好的钛/钢异种金属钎焊接头，未见明显的焊接缺陷；硬度测试发现钛/铜界面处的硬度明显升高，这与钛/铜区域易形成Ti-Cu金属间化合物有关；钎焊接头的断裂发生在铜/钛侧，断裂方式属于韧-脆混合断裂，抗拉强度为291.55 MPa，约为铜钎料强度的88%.

Abstract:

The titanium and steel dissimilar metals were brazed by bypass-current arc welding with S211 copper alloy as filler metal. The macro and microstructure, element distribution, and tensile strength of the brazed joints were analyzed by using optical microscopy, scanning electron microscopy, universal tensile testing machine and other technologies, and the hardness distribution of joint was analyzed by using a micro-hardness tester. A well brazed joint of titanium/steel was obtained, and no obvious welding defects were found. Hardness test found that the hardness in the titanium/copper area was significantly increased, and this was related to the easy formation of Ti-Cu intermetallic compound in the titanium/copper area. The fracture of the titanium/steel brazed joint occured on the copper/titanium side, the fracture mode was ductile-brittle mixed fracture, and the tensile strength reached 291.55 MPa, which was about 88% of the strength of the copper solder.