异种金属材料扩散连接研究进展

Research advances in the diffusion bonding of dissimilar metals

摘要:

为满足现代高端装备对结构性能与轻量化的双重要求,异种金属材料的高可靠连接已成为先进制造领域的核心挑战之一。扩散连接作为一种先进的固相连接工艺,通过热-力耦合作用促使界面原子互扩散实现冶金结合,尤其适用于物理化学性质相差巨大的异种材料组合,在航空航天、新能源及核能等高端工业领域展现出不可替代的应用价值。本文系统综述了异种金属扩散连接的研究现状与进展。首先,依据材料组合的冶金相容性,将异种金属扩散连接体系分为3类:相容性良好体系（如异种钢、钢/镍等）、相容性差体系（如铜/铁、钨/铜等）,以及易生成脆性金属间化合物（intermetallic compounds, IMCs）体系（如钢/钛、钛/镍、铝/钢等）,并分别阐述了其连接机理与主要技术难点。其次,研究重点围绕钢、镍、钛、铜、铝、镁等关键工程材料的组合展开,深入探讨了如何通过工艺参数优化、工艺方法创新、中间层设计及表面预处理等策略实现对界面反应、IMCs生长及残余应力的调控作用。研究发现,选择合适的中间层（如Ni、Cu、Ag、高熵合金等）能够有效抑制有害IMCs的生成,并缓解热膨胀系数差异带来的热应力,从而显著提升接头性能；而表面纳米化等预处理技术可实现高质量低温连接,抑制材料热损伤。最后,本文展望了该领域的未来重点研究方向,包括界面反应动力学的多尺度模拟、低应力无缺陷新工艺开发,以及人工智能在材料设计与工艺优化中的应用,以期为推动扩散连接技术在高端工业领域的更广泛应用提供理论参考和技术支撑。

Abstract:

To meet the dual requirements of structural performance and lightweight design in modern high-end equipment, high-reliability joining technologies for dissimilar metals have become one of the core challenges in the field of advanced manufacturing. Diffusion bonding, as an advanced solid-state joining process, enables interfacial atomic interdiffusion through thermo-mechanical coupling to achieve metallurgical bonding. It is particularly suitable for joining of dissimilar materials with significantly different physical and chemical properties, and holds unique value in high-end industrial fields such as aerospace, new energy, and nuclear industry. This paper systematically reviews the current state of research and progress in diffusion bonding of dissimilar metals. Firstly, based on the metallurgical compatibility of material combinations, dissimilar metal diffusion bonding systems are categorized into three types: systems with good compatibility (e.g., dissimilar steels, steel/nickel, etc.), systems with poor compatibility (e.g., copper/iron, tungsten/copper, etc.), and systems prone to forming brittle intermetallic compounds (IMCs) (e.g., steel/titanium, titanium/nickel, aluminum/steel, etc.). The bonding mechanisms and principal technical challenges for each category are discussed in detail. Secondly, the study focuses on combinations of key engineering materials such as steel, nickel, titanium, copper, aluminum, and magnesium alloys, and examines strategies for controlling interfacial reactions, IMC growth, and residual stresses through optimized process parameters, innovative process methods, interlayer design, and surface pretreatment. Research shows that selecting appropriate interlayers (e.g., Ni, Cu, Ag, high-entropy alloys, etc.) can effectively suppress the formation of harmful IMCs and alleviate thermal stresses caused by differences in thermal expansion coefficients, thereby significantly improving joint performance. Pretreatment techniques such as surface nanocrystallization enable high-quality low-temperature bonding while minimizing thermal damage to materials. Finally, this paper highlights future key research directions in the field, including multi-scale simulations of interfacial reaction kinetics, development of low-stress and defect-free new processes, and the application of artificial intelligence in material design and process optimization, aiming to provide theoretical references and technical support for promoting the wider application of diffusion bonding technology in high-end industrial fields.