The Interface Quality of Copper Clad Steel Wire Produced by Liquid-solid Bonding Process

The influences of preheating temperature and surface treatment method on interface of copper clad steel wire produced by liquid-solid bonding process were studied.Increasing preheating temperature improved the bonding strength of Cu/Fe at the interface.However,the bonding strength decreased due to oxidation at the surface of steel wire when the preheating temperature was beyond 300-400 ℃.It could reach 95 MPa as the steel wire was preheated to 400 ℃ and treated with acid and mechanical cleaning and plated with halide solution as well.Microstructure observation showed that the grains of copper and steel were in contact directly.In addition,SEM morphology and composition distribution at the torn fracture area indicated that the torn fracture nearly occurred in the copper layer and the copper adhered to steel core was well distributed,which promoted the bonding strength to approach or even surpass the shear strength of pure copper.