扩散连接接头金属间化合物新相的形成机理

Forming Mechanism of interface intermetallic Compounds for Difusion Bonding

扩散连接接头中界面区脆性金属间化合物相的出现往往会造成接头性能的恶化 ,因此研究并建立接头界面区金属间化合物相的生成和成长行为的数学模型对扩散连接过程控制有非常重要的理论及现实意义。本文根据扩散理论 ,指出界面处生成相的动力学驱动力取决于扩散偶中组元自身的特性 ,生成相的组元及比例应按原子扩散通量比优先生成。本文从动力学及热力学角度出发 ,提出了多组元扩散偶界面处的金属间化合物生成相原则 :通量 -能量原则 ;并以钛 镍 钢扩散连接接头为例 ,证明钛 镍界面处金属间化合物相的生成规律为Ni TiNi3 TiNi Ti2 Ni Ti。提出 ,通量 -能量能力相当的两种或多种金属间化合物有可能同时形核长大 。

The formation Of brittle intermetallic compounds at the interfaces of diffusion bonds is the main cause which lead to produce poor bond properties. Therefore, it is very important to research on and establish the formation and growing model Of intermetallic compounds at the interfaces for the control process of diffusion bonding. In this paper,according to the diffusion dynamics and the thermodynamics,the formation principle of interface intermetallic compounds for the multi composition diffusion couple,the flux energy principle,was put forward. In the light of diffusion theory, the formation capacity of the phase at the interfaces is determined by specific properties of the composition in the diffusion couple and the composition proportion of the formed phase is in agreement with the atom diffusion flux. In accordance with the flux energy principle, the microstructure of the Ni/Ti interface is Ni/TiNi 3/TiNi/Ti 2 Ni/Ti. On the basis of this paper theory,multi intermetallic compounds with the equivalent flux energy can be formed at the interfaces at the same time.