基于高熵效应的镁铝异质金属焊接组织演变及界面反应机制研究

项目名称： 基于高熵效应的镁铝异质金属焊接组织演变及界面反应机制研究

项目编号： No.51205039

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 机械工程学科

项目作者： 任大鑫

作者单位： 大连理工大学

项目金额： 25万元

中文摘要： 镁、铝合金是目前最轻的两种工程金属结构材料，二者的连接可以减轻结构重量，提高航天器和汽车等运载工具性能。然而，镁铝异质金属在焊接过程中极易生成高脆性金属间化合物层，严重恶化接头力学性能。高熵效应可以抑制金属间化合物的生成，使材料具有晶体结构简单、机械性能优良等特点。本申请项目以高熵效应理论为基础，将多主元高熵效应引入到镁铝异质金属焊接中，通过形成高熵化合金焊缝，提高镁铝异质金属焊接接头强度。本项目将分析合金元素之间的相容性规律及形成高熵合金的成分条件窗口，揭示高熵合金焊材元素选择及配比设计机制；利用高熵合金焊材对镁铝异质金属进行焊接，分析微观组织与力学性能之间内在联系，揭示高熵化合金焊缝组织演变规律以及界面反应机制，通过热力学对高熵效应焊接进行理论分析，形成基于高熵效应的镁铝异质金属焊接工艺体系。本研究将为镁铝异质金属的高强度连接提供理论依据，为异质难焊金属的连接提供新思路和新方法。

中文关键词： 镁合金；铝合金；金属间化合物；合金化焊缝；微观组织

英文摘要： Magnesium alloys and aluminum alloys are the lightest two structural metallic materials, and their joint can reduce the structure weight to increase the performance of spacecraft and vehicles. However, brittle intermetallic compound layer can be easily formed when welding Mg and Al, and serious deteriorate the mechanical properties of the joints. High-entropy effect can inhibit the formation of intermetallic compounds, and make the material have relatively simple crystal structures, and besides, the high-entropy alloys have excellent mechanical properties. The research of this application is based on the high-entropy effect theory, and the high-entropy effect is introduced into welding of Mg and Al. It is expected to form the weld of high-entropy alloy, in order to increase the strength of Mg-Al joint. In this application, the compatibility law between the alloying elements is analyzed, and the mechanisms of element selection and composition design are researched, and the high-entropy welding consumables can be produced based on the mechanisms. The high-entropy welding consumables can be used to weld Mg and Al, and the relation between the microstructures and the mechanical properties is researched. The microstructural evolution and interfacial reaction mechanism of the high-entropy weld are revealed, and the th

英文关键词： Magnesium alloy；Aluminum alloy；Intermetallic compounds；Alloying seam；Microstructure