钛合金连接异种材料新技术的研究应用

Progress in Welding of Titanium Alloy and Dissimilar Materials

钛合金作为新型结构材料,具有简单的耐热性、高比强度和韧性,已不能满足航空航天军工等飞速发展的高科技领域,与异种材料连接组成低成本、综合性能优异的结构件是匹配高要求的捷径。异种材料间性质,如熔点、热传导率、表面抗氧化能力等的差异是较好实现连接两者的难点,选择不同焊接技术则是解决问题的关键。传统的电弧焊、氩弧焊、CO2保护焊等对原材料污染严重且焊接强度低,而新型的搅拌摩擦焊、瞬间液相扩散焊、高能束流焊等可以克服异种材料间性质的差异,同时针对钛合金表面极易氧化的缺点,利用真空环境及保护气体很好地提高了焊接接头强度,而且环保节能。重点分析利用搅拌摩擦焊、瞬间液相扩散焊等新型技术实现钛合金与非金属及金属异种材料连接过程中,不同技术存在的优劣,总结研究现状,并提出了未来钛合金连接异种材料的发展方向。

As new structural materials, titanium alloys with the heat resistance, high specific strength and high toughness could not meet the rapid development of high-tech area, such as aerospace, military industry and so on. The shortcut to match high demand was to weld titanium alloy with dissimilar materials. The difficulty of welding was the different properties （ melting point, thermal conductiv- ity, surface oxidation resistance, etc. ） between titanium alloy and dissimilar materials. So to select welding method was the key to solve problems. The traditional welding methods, such as arc welding, argon arc welding, C02 protection welding, etc. , had the short- comings of raw materials pollution and low strength of welding. The new types of friction stir welding, transient liquid phase-diffusion bonding and high energy beam welding could overcome the different properties between dissimilar materials. Vacuum environment and protective gas could help to avoid titanium alloy surface oxidation easily. Meanwhile, they could obviously improve the strength of welding joint with environmental protection and energy saving. This work mainly analyzed the advantages and limitations in the process of welding titanium alloy with nonmetallic and metallic dissimilar materials by new types of friction stir welding, transient liquid phase- diffusion bonding and high energy beam welding, etc. , and the future development direction was put forward.