In the process of modern manufacturing's transformation towards high-end and diversified production, single-metal materials are no longer sufficient to meet the comprehensive performance requirements of complex working conditions. Dissimilar metal joining technology has emerged to address this need. It reliably combines two or more metals with significantly different physicochemical properties through physical, chemical, or metallurgical methods, achieving complementary performance advantages and becoming an indispensable core supporting technology in aerospace, automotive manufacturing, energy, and chemical industries.
The core challenge of dissimilar metal joining lies in overcoming the mismatch in thermal expansion coefficients, crystal structures, and chemical compatibility between different metals, and avoiding defects such as brittle phases, electrochemical corrosion, or stress deformation at the joining interface. Currently, mainstream joining technologies can be divided into four main categories, each with its own focus and widely applied in different scenarios. Mechanical connections achieve fixation through physical interlocking methods such as riveting and screwing, balancing lightweight design and maintainability, and are commonly used in lightweight automotive body assembly. Metallurgical connections utilize high-temperature melting interfaces to achieve atomic-level diffusion, such as laser brazing, suitable for high-strength connections of critical aerospace components. Adhesive connections use the adhesive force of polymer adhesives to form continuous adhesive layers, adapting to the connection requirements of precision electronic components. Solid-state connections achieve bonding through pressure and friction without melting the materials, such as friction stir welding, effectively reducing the heat-affected zone and protecting sensitive metal materials.
Today, the application of dissimilar metal joining technologies has permeated every corner of high-end manufacturing. In the automotive industry, the connection of steel and aluminum alloys achieves lightweight vehicle bodies, contributing to energy conservation and emission reduction; in the aerospace industry, the reliable connection of titanium alloys and high-temperature alloys ensures the safe operation of aircraft in extreme environments; in the energy and chemical industry, the connection of stainless steel and heat-resistant steel meets the corrosion resistance and pressure resistance requirements of high-temperature and high-pressure pipelines; in the electronics and information industry, the connection of copper and steel balances conductivity and structural strength, supporting the stable operation of precision components.
With the upgrading of industrial demands, dissimilar metal joining technology is iterating towards integration, intelligence, and greening. Breakthroughs in technologies such as laser-arc hybrid welding and intelligent parameter control have further improved the quality and efficiency of joining; low-smoke, low-emission green processes align with the environmental protection industry trend; and machine learning-based process optimization and quality monitoring are driving the technology towards precision and efficiency. Currently, the global dissimilar metal joining market continues to grow, with continuous technological innovation breakthroughs gradually solving core challenges such as interface control and performance stability.
As a "bridge" connecting different metal materials, dissimilar metal joining technology not only promotes the diversification of material applications but also helps the manufacturing industry overcome performance bottlenecks and reduce production costs. In the future, with the deepening of multidisciplinary integration, this technology will achieve breakthroughs in more emerging fields, injecting stronger momentum into the high-quality development of high-end manufacturing.
