Collaborative improvement of mechanical and electrical properties of Cu–Ni–Co–P alloys via regulation of nanophase precipitation behavior

Abstract

Owing to their excellent strength and electrical conductivity, Cu–Ni–Co–P alloys present strong potential as next-generation materials for integrated circuits in electronic information systems. However, these outstanding properties are closely tied to the precise control of nanophase precipitation behavior within Cu-based alloy systems. Herein, the design of alloy composition was combined with aging treatment to regulate the nanoprecipitation process. Furthermore, the effects of P content and aging treatment conditions, including temperature and duration, on the microstructure and the mechanical, and electrical properties of Cu–Ni–Co–P alloys were systematically investigated. The findings reveal that Cu–0.3Ni–0.3Co–0.16P alloys, when aged at 500 °C for 4 h, primarily consist of a Cu-rich matrix interspersed with numerous nanoprecipitates. These nanoprecipitates were identified as the hexagonal CoNiP phase, precipitating in Guinier–Preston (GP) zones and maintaining a coherent relationship with the Cu matrix. The as-annealed Cu–0.3Ni–0.3Co–0.16P alloys demonstrated a tensile strength of 652.9 MPa, a yield strength of 631.2 MPa, a Vickers hardness of 203.2 HV, and an electrical conductivity of 66.4 %IACS. Aberration-corrected scanning transmission electron microscopy revealed that G.P. zones suppressed the coarsening of the CoNiP phase, thereby enhancing the mechanical strength of the Cu–Ni–Co–P alloys. The strength analysis calculations suggest that fine-grain and precipitation strengthening mechanisms are the predominant factors in improving the mechanical strength of these alloys. This study provides valuable insights into the development and manufacturing of high-performance Cu-based alloys for advanced applications in the electronics industry.