Experimental study on mechanical and chemical behaviors of bi-layer Fe/Al sheet after laser forming

Abstract

Laser forming process is a modern method of bending sheet metal workpieces based on thermal stresses and strains. In this article, chemical, mechanical, and physical behaviors of bi-layer Fe/Al workpieces before and after laser forming process were investigated. In order for the corrosion study, the workpieces which underwent laser forming were studied through two different methods of salt spray and polarization. Then, by providing the bone-shaped specimens, the tensile tests were conducted and the mechanical behavior of the laser formed workpieces was investigated. Afterwards, their structures were screened using metallographic images. The number of laser passes was increased in each step of investigation. Results obtained from salt spray experiment indicated that this action would raise the corrosion resistivity of workpieces; consequently, a little amount of corrosion would be revealed in them. Moreover, the results obtained from polarization experiments also indicated that increasing the number of laser passes would lead to the reduction in the absolute value of corrosion potential. Furthermore, it was revealed that increasing laser passes resulted in declining elongation and, conversely, boosting grain size and ultimate tensile strength.