基于热物理模拟的钢/铝异种金属熔钎焊界面反应与力学行为调控机理研究

项目名称： 基于热物理模拟的钢/铝异种金属熔钎焊界面反应与力学行为调控机理研究

项目编号： No.51475040

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 机械、仪表工业

项目作者： 陈树海

作者单位： 北京科技大学

项目金额： 83万元

中文摘要： 本项目针对钢/铝异种金属熔钎焊界面微观组织可控性差、接头力学性能不稳定等问题，提出一种方便精确定量研究异种金属固/液界面反应机理的热物理模拟研究方法，拟开展界面反应与力学行为调控机理研究，解决初始阶段的固/液界面反应机理、热循环条件下界面反应动力学及合金元素作用机制和界面脆性金属间化合物层近域力学行为三个关键基础科学问题。在研究恒温下钢/铝异种金属初始阶段的固/液界面反应机理并建立动力学模型的基础上，采用比较法建立热循环条件下的界面反应动力学模型，并研究合金元素对该动力学模型的影响机制，揭示熔钎焊固/液界面反应调控机理。以界面断裂韧性作为主要评价指标，通过裂纹萌生与扩展的原位观察、界面脆性金属间化合物层厚度与形态对界面断裂韧性影响的测试与模拟分析，揭示界面脆性金属间化合物层邻域的力学行为。本项目对提高钢/铝异种金属界面组织性能可控性与评估接头使用性能具有极其重要的理论意义。

中文关键词： 钢/铝异种金属；熔钎焊；界面反应；调控机理；力学行为

英文摘要： In order to improve the problems of bad controllability of interfacial microstructures and instability of mechanical properties of the welding-brazing joint of Fe/Al dissimilar metals, this project proposes a thermal physical simulation research method to investigate conveniently and quantitatively dissimilar metals solid/liquid interfacial reaction mechanism. The regulation mechanism of interfacial reaction and mechanical behavior is investigated to solve three key issues of solid/liquid interfacial reaction in initial stage, interfacial reaction kinetics at thermal cycle and influence mechanism of alloying element, and mechanical behaivior in the neighborhood of brittle interfacial compounds layers. The solid/liquid interfacial reaction mechanism of Fe/Al dissimilar metals in initial stage is investigated and its kinetics model is established. Furthermore, the interfacial reaction kinetics model under the condition of thermal cycle is proposed by comparative method. And, influence mechanism of alloying element on the model is clarified. The regulation mechanism of solid/liquid interfacial reaction for Fe/Al dissimilar metals welding-brazing is revealed. Using fracture toughness as assessment criteria, the influence mechanism of thickness and morphology of brittle interfacial intermetallic compounds layers on interfacial mechanical behavior is clarified by in site observation on initiation and propagation of the cracks, tests and simulation analysis on the interfacial toughness. The interfacial mechanical behavior in the neighborhood of intermetallic compounds layers is revealed. This project has important theoretical significance for enhancing controllability of interfacial structures and properties and evaluating availability of the joint.

英文关键词： Fe/Al dissimilar metals;welding-brazing;interfacial reaction;regulation mechanism;mechanical behavior