Microstructure Evolution of H62 Copper Alloy and T2 Pure Copper in Different Plastic Deformation under Tensile Loading

Uniaxial tensile tests were carried out on T2 pure copper plate and H62 copper alloy subjected to identical heat treatment. The influences of different strain states on the damage degree of both materials were analyzed. It is found that the fracture and damage of T2 pure copper and H62 copper alloy are closely related to their microstructure under tensile loading. The shape factor of the studied materials shows a similar variation trend with increasing strain, while shape factor for H62 copper alloy is larger than that for T2 pure copper. Evolution of relative shape factor for the studied materials shows very similar variation. In the present work, a damage variable of shape factor of grains was put forward to quantitatively describe the character of microstructure; its evolution with the plastic deformation was built-up by micro-analytical and mechanical experiments for T2 pure copper plate and H62 copper alloy. By virtue of exponential function, the normalized shape factor curves of the studied materials were fitted and the fitting equations were established, which reveals the relationship between the macroscopic deformation and microstructure of materials.