Effect of normal load and strain accumulation on tribological properties of Al3003/St12 multilayered composite produce by severe plastic deformation

Developing novel methods for manufacturing multilayered composites has been the central effort of researchers for years. This study presents the fabrication of Aluminum/steel/Aluminum (Al/St12/Al) multilayered composites using the accumulative roll bonding (ARB) technique, with an examination of the impact of normal load and strain accumulation on microstructure, mechanical properties, and tribological properties. As the applied accumulative strain increased, more instabilities were detected in the St12 layers, with no defects present. The mechanical properties exhibited enhancements as the ARB passes increased, with ultimate and yield strength values as well as microhardness rising, while elongation decreased due to the uneven distribution of hard layers within the Al matrix. The composite achieved a maximum ultimate tensile strength (UTS) of 260 MPa and a breakpoint elongation of 7% after six passes. Scanning electron microscopy (SEM) images revealed both ductile and cleavage fracture modes on the surfaces. Also, based on the results of wear tests, the application of higher accumulative strain improves wear resistance while normal load deteriorates it. Moreover, wear tests indicated various wear mechanisms, including adhesion, abrasion, and delamination, with a reduction in weight loss observed with an increase in the number of rolling passes attributed to the increased hardness of the strain-hardened layers.