Microstructural evolution and mechanical properties of pure copper by caliber rolling

Caliber rolling (CR) is a extensively employed in the mass production of fine-grained metals, with applications spanning various industrial fields. This study investigates the effects of multiple caliber rolling passes on the microstructural evolution and mechanical properties of pure copper (Cu) at ambient temperature. The results indicate that CR effectively refines grain size, predominantly through the fragmenting the original grains. After 3 passes, the average grain size (AGS) decreases, leading to enhanced mechanical properties, i.e., the yield strength (YTS), ultimate tensile strength (UTS), and elongation (El.) of pure Cu are 171 MPa, 430 MPa, and 17.7 %, respectively. In comparison to as-extruded one, the YTS and UTS exhibited increases of 54.4 % and 51.2 %. The improvement in mechanical properties is primarily attributed to grain refinement and dislocation strengthening mechanisms. However, after 5 passes, the influence of grain refinement becomes more significant than dislocation strengthening, resulting in a decline in strength.