Study On Cold Roll Bonding Of Brass/Copper/Brass

Clad sheets of complex copper alloy is mainly used in the decoration, coin and other fields. According to the problems that complex brass have low plasticity, bad corrosion resistance, and it is difficult to cold roll bonding, some complex brasses was designed in this paper. A brass was selected to process clad sheets for coin by testing their mechanical properties and corrosion resistance, and cold rolling bonding. The conclusions are following:Recrystallization takes place, annealing twin formed and grains grow in the HAL77 brass cold rolled with increase in annealing temperature, which results strength of the brass decreases and increase in plasticity. With increase in annealing time at a constant temperature, strength of the brass deceases and plasticity of the brass increases. When the annealing time is to long the plasticity decreases because of abnormal growth of grains. Strength obviously decreases and plasticity increases remarkable in the brasses processed in this study when annealed at 750℃ forlhr. They were cold rolled without cracks at reduction 75%.When the content of Ni is 0.5wt% strength of brass bearing Al has higher strength and plasticity after annealing.Increase in Zn content can improve the strength and plasticity in the brass with only a phase.Surface processing and annealing parameter is key process for cold clad rolling, especially the surface processing. Combining of mechanical processing and chemical treatment can remove oxides drastically on the surface. The metallurgical bonding formed and bonding strength increases because of the alloying elements diffusion and formation of a diffusion layer in the interfaces of clad sheets after annealing at 800℃ for 1.5hr.