Interfacial Strength Enhancement of Diffusion-Bonded High-Strength Low-Alloy Steel Using Beryllium-Copper Alloy as an Interlayer

Abstract

This study focused on optimizing the diffusion bonding variables to produce the highest inter-laminar shear strength of steel joints using a beryllium-copper (Be-Cu) alloy interlayer. Diffusion bonding, a sophisticated and advanced manufacturing technique, allows for the precise joining of materials by operating below their melting temperatures, thus preserving their inherent properties and preventing the formation of undesirable phases. The results demonstrated that inter-laminar shear strength varied significantly depending on the bonding parameters. Notably, the highest inter-laminar shear strength was achieved at 750 °C with a hold time of 2 h. At this temperature, the bond strengths of samples containing Cu and Be-Cu as interlayers were substantially higher than those of High-Strength Low-Alloy (HSLA) steel samples bonded without any interlayer. This finding highlights the potential for bonding HSLA steel at much lower temperatures. Furthermore, HSLA steel bonded at 750 °C with a Be-Cu interlayer exhibited significantly greater shear strength compared to those bonded with a Cu interlayer, thereby establishing the superiority of Be-Cu as an interlayer material over Cu. The use of Be-Cu alloy, with its exceptional thermal and electrical conductivity, high strength, and corrosion resistance, greatly enhanced the effectiveness of diffusion bonding in HSLA steel joints. These results pave the way for improved structural performance in critical engineering applications, underscoring the importance of advanced manufacturing techniques in modern engineering.