Laser Applications in Ceramic and Metal Joining: A Review

Ceramics and metals are both common materials applied in various industries, due to their unique characteristics in terms of physicochemical and mechanical properties. Recently, ceramic–metal components with the attractive and excellent performance have gained popularity, and have been extensively exploited in aerospace, microelectronics and medical. However, conventional ceramic/metal joining methods, such as brazing, diffusion welding and friction welding, often lead to problems involving thermal residual stresses and impaired joint strength owing to mismatches in thermal expansion and interfacial bonding nature. Laser technique with the benefits of high precision, energy concentration and fast processing plays an increasingly prominent role in the joining of ceramics to metals. This review investigates the applications and limitations of brazing, diffusion welding and friction welding for the joining of ceramic to metal. Comprehensive analysis in the progress of research on continuous-wave laser joining, laser-assisted joining and pulsed laser joining of ceramic to metal is critically reviewed. The effects of laser parameters on the quality of joint are studied. Chemical properties, phase diagram, microstructure, mechanical properties and electrical conductivity of metal/ceramic joints are systematically discussed, and some observations are reported. Finally, the article provides an overview on potential future strategies for laser joining of ceramics to metals, offering a creative thought for the fabrication of metal–ceramic composite structures. Therefore, this work can serve as the basis for the research of laser joining ceramics and metals.