Investigation of forming limit of multi-layered composite processed by roll bonding method

In the past two decades, the development of layered composites as well as their manufacturing methods has become a fascinating subject for researchers. The CRB is a solid-state welding to create a bonding between a wide ranges of metals using a simple rolling. In this study, the multi-layered Al5052/MgAZ31B composite was produced by CRB and its formability was studied. Rolling operations were performed by applying a 70% reduction in room temperature. The formability of Al/Mg composite was carried out using stretch test with semi-circular punch in different loading and the forming limit diagram was drawn. FLDs are the most practical method for obtaining sheet formability, which determines the strain before necking and fracture. In addition to formability, mechanical properties and fracture surface of Al/Mg were also studied using a tensile test, microhardness, optical and scanning electron microscopy. Due to low formability of magnesium and the production of Al/Mg composite at room temperature, the surfaces of the FLD is desirable due to the lack of separation between the aluminum/magnesium interfaces and the compensation tightness of magnesium with high formability of aluminum. Also, the results of mechanical properties showed that strength and microhardness of Al/Mg composite compare to initial aluminum improved 149.5% and 80%, respectively, due to the cold working and increasing density of dislocations. The images of the fracture surfaces showed that the aluminum before and after rolling had a ductile fracture with different size, number of dimples that after the rolling the size and depth of the dimples decreased.