温度对AgCu/光滑TC4体系润湿铺展动力学的影响

Wetting Kinetics of AgCu/Polished TC4 Substrate System with Different Temperatures

研究了试验温度对AgCu/光滑TC4钛合金体系的润湿铺展动力学的影响,实验过程采用座滴法,全程高纯氩气保护。结果表明,试验温度的升高明显促进了AgCu/光滑TC4体系的润湿性和界面反应。当试验温度为1103和1133 K时,AgCu钎料在TC4基板上的润湿铺展过程相似,整个润湿铺展过程大致可分为4个阶段:初始阶段,快速铺展阶段,缓慢铺展阶段和渐进平衡阶段。当试验体系温度为1213 K,化学反应更为强烈,AgCu钎料在TC4基板上的润湿铺展速度明显地加快,整个润湿铺展过程缩短至3个阶段:初始阶段,快速铺展阶段和渐进平衡阶段。试验温度为1103和1133 K时,钎料熔敷/母材的界面结构均为残余的富银相/Ti_3Cu_4/富钛相+Ti_2Cu/TC4基板;当试验温度为1213 K时,其界面结构转变为残余的富银相/Ti_3Cu_4/Ti_2Cu/富钛相+Ti_2Cu/TC4基板。且随着温度的升高,各个界面反应层的厚度均增加,残余的富银相厚度减小。AgCu钎料在光滑TC4基板上的润湿铺展动力学遵循Rn^t模型,试验温度不同,n值有所变化。

The effects of temperature on wetting kinetics of AgCu filler metal over polished TC4 substrate under a high-purity argon atmosphere were investigated by the sessile drop technique. The results showed that the elevation of temperature obviously promoted the wettability and interfacial reaction. When the spreading processes of AgCu over TC4 substrate were similar at 1103 and 1133 K,the entire spreading process could be divided into four stages： initial stage; rapid spreading stage; limited spreading stage; asymptotic stage.When temperature was 1213 K,the chemical reaction was more drastic and the spreading rate of AgCu over TC4 substrate rose distinctly,the entire spreading process became three stages： initial stage; rapid spreading stage; asymptotic stage. In the case of 1103 and1133 K,interface structure of brazed joint consisted of Ag-rich phase of residue filler metal/Ti3Cu4phase/mixture of Ti-rich and Ti2Cu phase/TC4 substrate,while a layer-structure of Ag-rich phase/Ti3Cu4phase/Ti2Cu phase/the mixture of Ti-rich and Ti2Cu phase/TC4 substrate was captured at 1213 K. The thickness of layer increased and Ag-rich phase decreased with temperature increasing. Wetting kinetics of AgCu/polished-TC4 followed power law of R^n- t,and value of n changed with temperature.