Enhancing strength and ductility of CuCrZr high-conductivity alloy via lamellar heterostructures on grain boundaries

Heterogeneous lamellar structure materials have attracted extensive attention due to their exceptional strength and ductility. In this study, Y element was introduced into CuCrZr alloys to adjust the liquid phase formation temperature of the CuZrY phase during the solution annealing process. By employing cold rolling deformation prior to annealing to elongate the grains, the liquid phase was promoted to wet the elongated grain boundaries during the annealing process, ultimately forming lamellar CuZrY heterostructures distributed along the grain boundaries. The heterogeneous lamellar structure, the grain boundary distribution characteristics, and the effect of Y on stacking fault energy enhanced the hetero-deformation induced working hardening, thereby improving both the strength and ductility of the CuCrZrY alloy. Besides, the investigated CuCrZrY alloy achieved an excellent combination of tensile strength, uniform elongation, electrical conductivity and thermal conductivity, with values of 527 MPa, 10.66%, 83% IACS and 335.5 W/(m·K), respectively. Therefore, the method of controlling liquid phase temperature through composition adjustment and liquid phase infiltration path through grain deformation offers new possibilities for the design of heterogeneous lamellar structure materials.