Two different thermo-mechanical processing routes, single-cold-rolling and double-cold-rolling, are adopted to process a Cu-Ni-Si alloy, and their effects on the microstructure and properties of the alloys are investigated. While keeping identical aging treatments and equivalent total cold-rolling deformation, 45-minute final aging at 450 °C endows the double-cold-rolling-processed alloys with a tensile strength of 754 ± 12 MPa, higher than 691 ± 3 MPa for the single-cold-rolling-processed alloys, whereas their electrical conductivities are close (~ 39 pct IACS). The final aging at 450 °C for 4 hours, on the other hand, renders the double-cold-rolling-processed alloy an electrical conductivity of 52.6 pct IACS, greater than 43.7 pct IACS for the single-cold-rolling-processed alloy, whereas their strengths are approximately identical (~ 705 MPa). The superior mechanical and electrical properties in the double-cold-rolling-processed alloy with the final aging time from 45 minutes to 4 hours are attributed to the dissolution of large precipitates during the second cold rolling followed by the acceleration of fine and uniformly dispersed precipitates in the final aging. Finally, the effects of dislocations, grain boundaries, solute atoms, and precipitates on the mechanical and electrical properties of the examined Cu-Ni-Si alloy are discussed on the theoretical basis, which can provide guidelines to further processing optimization.

中文翻译：

---

通过热机械加工增强Cu-Ni-Si合金的机械和电性能

采用了两种不同的热机械加工路线，即单冷轧和双冷轧来加工Cu-Ni-Si合金，并研究了它们对合金的组织和性能的影响。在保持相同的时效处理和等效的总冷轧变形的同时，在450°C下进行45分钟的最终时效赋予了双冷轧加工的合金以754±12 MPa的抗拉强度，高于691±3 MPa的抗拉强度。单冷轧加工合金，而它们的电导率却很接近（〜39 pct IACS）。另一方面，在450°C下进行的最终时效4小时使双冷轧加工合金的电导率为52.6 pct IACS，大于单冷轧加工合金的43.7 pct IACS，而它们的强度大致相同（〜705 MPa）。最终时效时间为45分钟至4小时的双冷轧合金具有优异的机械和电性能，这归因于第二次冷轧过程中大的沉淀物的溶解，随后加速了细小且均匀分散的沉淀物在最后的衰老中。最后，在理论基础上讨论了位错，晶界，溶质原子和析出物对所研究的Cu-Ni-Si合金的机械和电性能的影响，可为进一步的工艺优化提供指导。