铝合金厚板搅拌摩擦焊焊缝金属流动行为研究进展

搅拌摩擦焊接过程中,焊缝成形与金属流动行为密切相关,而金属流动又取决于焊接工艺参数、搅拌头形貌、材料本身性能及温度场分布等影响因素。与铝合金薄板搅拌摩擦焊不同,厚板焊接时焊缝上部、下部温差太大,导致焊缝材料流动形态发生较大变化。基于焊缝成形理论,从焊缝金属流动分析方法、影响因素出发,分析厚板搅拌摩擦焊焊缝金属流动形态及特征,探讨焊缝中疏松、未焊透、包铝伸入、弱连接等缺陷的形成原因,揭示厚板搅拌摩擦焊焊缝成形机理。研究结果为铝合金厚板搅拌摩擦焊焊接技术在航空、航天等高科技领域的广泛应用提供科学依据和理论基础。

Material Flow Behavior of Friction Stir Welding Aluminum Alloy Thick Plate Joint

During FSW processing, weld formation is related to material flow behavior which depends on welding process parameter, tool profile, material property, temperature field distribution, etc. Different from FSW of aluminum alloy sheet, the temperature difference of the top and bottom of weld is bigger when thick plates are welded, and which can result in a big change of weld metal flow pattern. Based on weld formation theory of FSW, the weld material flow and its characteristics were investigated from analysis methods and influencing factors of metal flow. Moreover, the formation reason of welding defects including looseness, lack of penetration, Al-cladding and weak connection, etc. were studied to reveal the formation mechanism of FWS thick plate joint. Finally, the study results provide scientific foundation and theoretical basis for the FSW technology of aluminum alloy thick plate used in high-tech fields such as aviation and aerospace fields in future.