Characterization of the Plastic and Elastic Properties of Aluminum Sheet Produced by CRB Process via DIC Method

The cold roll bonding (CRB) is a solid state welding process for bonding similar and dissimilar metals. The use of materials produced by the CRB method for different applications and the prediction of their behavior in simulation software requires the complete and accurate identification of their mechanical properties. Digital image correlation (DIC) is a powerful non-contact method for measuring the field of material deformation. Recently, the DIC method has been developed and widely used in various studies due to its advantages. In this research, two-layered aluminum alloy 1050 was produced via CRB process with applying 50% reduction of thickness at ambient temperature and then using the 2D-DIC system to extract distribution of the strain field during the uniaxial tensile test at rolling direction. Strain in two directions of length and width was calculated, using DIC and strain in terms of thickness, effective strain, and anisotropy coefficient, using plasticity relationships. Moreover, for the first time, using the virtual field methods (VFM), elastic and plastic parameters such as elastic modulus, Poisson ratio, strength coefficient, strain hardening exponent, and yield stress were calculated. The results showed that the strength and microhardness were significantly increased due to the work hardening and increasing the density of dislocations, and the elongation and strain hardening exponent were reduced. The strength for the two-layered aluminum was 113MPa, which improved more than three times of the initial aluminum. Also, changes in the elastic parameters were very small and the modulus of elasticity for the primary aluminum and two-layered aluminum was 69.3 and 70GPa, respectively.