Characterizing the elastic and plastic properties of the multilayered Al/Brass composite produced by ARB using DIC

In the present study, for the first time, Young's modulus, anisotropy coefficient in the rolling direction and other elastic and plastic parameters of multi-layered Al/Brass composite produced by ARB process were assessed by DIC method. DIC as a non-contact accurate and powerful method for measuring deformation and strain field of material can calculate various material parameters such as anisotropy and Young's modulus. Anisotropy and Young's modulus are the basic parameters in the design of structures and manufacturing analysis, especially forming processes, in the calculation of spring back. Multi-layered Al/Brass composite has been fabricated using the ARB process. Moreover, the microstructure and mechanical properties have been determined by optical microscopy (OM), micro-hardness measurements and tensile tests equipped by 2D DIC system. Results have shown that the proper bonding between the Al/Brass interfaces was made in the primary sandwich and became stronger by increasing the imposing strain. Also, after the primary sandwich, plastic instability was observed in the brass layer. In addition, the structure for the primary sandwich was transformed from lamellar to wavy for the final pass. The tensile strength and microhardness of both layers have increased severely and continuously but after initial sandwich the rising trend has decreased. Results of DIC showed that by increasing the number of ARB passes, the young modulus increased, but the trend of anisotropy coefficient variation was exactly the same for all three ARB passes. As a result, after a rising and the sinusoidal oscillation, the anisotropy coefficient gradually decreased. Theoretical models were also used in order to estimate the elastic modulus of Al/Brass composite. The outcome results have shown that there is no good agreement between theoretical relations and experimental data for calculation the elastic modulus, because the theory relations are based on the volume of composite materials and it is not suitable for materials with a layered structure.