Suzuki, in 1952, proposed that the defects in a material with a different crystal structure from the parent structure act as prominent sites for the segregation of solute atoms due to the chemical interaction. This helps in explaining some of mechanical properties which are not explained by Cottrell's theory. In this atomistic modelling study, by coupling the molecular dynamics and the Monte Carlo simulations, we study the segregation of solute atoms to the stacking faults in Cu-Al alloys and the difference in the mechanical behaviour with and without segregation. We also rationalize the differences in mechanical behaviour by evaluating the stacking fault energy (SFE) before and after the segregation of the solute atoms to the stacking fault. In this presentation, we will also explain the thermodynamic integration methodology to evaluate the SFE and describe the stress-strain curves by correlating the same with the microstructures. Further, we will extend the methodology of coupling MD-MC to understand the recovery in commercially pure copper and copper-aluminum alloys in order to explain some of our experimental observations on Cu and Cu-Al alloys.