Accelerating Discontinuous Precipitation to Increase Strength by Pre-Deformation in Cu-Ni-Si Alloys.

Abstract

Discontinuous precipitation-strengthened Cu-Ni-Si alloys are highly regarded for their combination of high strength and excellent electrical conductivity. However, the slow process of discontinuous precipitation, typically requiring up to 24 h for complete formation, significantly increases the alloy's production costs and limits potential improvements in its properties. This study addresses this issue by applying pre-deformation to Cu-6Ni-1.42Si alloys, which accelerated the discontinuous precipitation (DP) of Ni₂Si by approximately 48 times, resulting in the formation of fast DP and full DP alloys. The fast DP alloy exhibited a smaller DP size and inter-distance than the full DP alloy, achieving a tensile strength of 1070 MPa and a conductivity of 38.5% IACS. In contrast, the full DP alloy had a slightly lower tensile strength (approximately 930 MPa) but a higher conductivity of 46% IACS. Both alloys outperform traditional Cu-Ni-Si alloys in strength while maintaining comparable conductivity. The accelerated DP technique improves mechanical properties without significantly sacrificing conductivity, offering a new approach for high-performance conductive materials.