Achieving an ultrastrong yet ductile copper alloy via microstructural heterogeneity with dense ordered nanoprecipitates
Rui Zhong, Weiwen Zhang, Chao Zhao, Zongqiang Luo, Haokai Dong
Abstract
Cast Al-containing cupronickel alloys are strong, corrosion resistant and anti-bio fouling, yet suffering from poor ductility due to intergranular brittle phase and inhomogeneous intragranular precipitation. Here, we employ industrial accessible powder hot extrusion to achieve an ultrafine hierarchically microstructural tailoring of a Cu-17Ni-3Al based alloy, enabling an unprecedented strength-ductility combination (1.1 GPa ultimate strength with 21% elongation). The exceptional mechanical property is resulted from the homogeneous L12 nanoprecipitates and heterogeneous matrix created by the interactions between fragmented G phase and dynamic recrystallization. These findings highlight the potential of heterostructure engineering with ordered nanoprecipitates for optimizing mechanical performance of Cu alloys.