Effect of Roughness and Surface Hardening on the Mechanical Properties of Three-Layered Brass/IF Steel/Brass Composite

In this research, three-layered brass/IF steel/brass composite produced by cold roll bonding (CRB) process was investigated. The effect of roughness and surface hardening of each layer on the mechanical properties of three-layered composite were separately examined. For this purpose, five rotatory wire brush models were used in order to prepare the surfaces for CRB process. The peeling and shear punch tests were also used to evaluate the mechanical properties of samples. Finally, optical and scanning electron microscopes were used to evaluate the fracture surfaces. The chemical compositions were analyzed at the joint interface by an energy dispersive X-ray analysis. It was observed that, decreasing the diameter of the brush enhanced the roughness and surface hardening. However, the increase in roughness and surface hardening of brass were less than that of IF steel due to different wear mechanisms. The results showed that, at the same reduction, the bond and shear strengths of composite were enhanced by increasing the surface roughness of each layer. Also, increasing the brass surface roughness had more effect on the bond strength of the strips due to its vital role in bonding formation in CRB processing. Moreover, rising the surface roughness of IF steel in comparison to brass had more influence on the shear strength of the composite.