Wu Dan, Hu Jinming, Hu Qiang, Wu Lingkang, Guan Bo, Zeng Siqi, Xing Zhen, Wang Jiahao, Xu Jing, Huang Guojie, Liu Jin
Jiangxi Key Laboratory of Advanced Copper-Based Materials, Institute of Applied Physics, Jiangxi Academy of Sciences, Nanchang 330096, China.
State Key Laboratory of Nonferrous Metals and Processes, GRIMAT Engineering Institute Co., Ltd., Beijing 101407, China.
Materials (Basel). 2025 Jul 10;18(14):3263. doi: 10.3390/ma18143263.
Cu-Ni-Si is a prominent example of a high-end lead frame copper alloy. The enhancement of strength without compromising electrical conductivity has emerged as a prominent research focus. The evolution of the precipitates exerts a significant influence on the strength and electrical conductivity of Cu-Ni-Si-Co-Mg alloys. In this paper, the effects of aging treatment and Mg addition on the properties and precipitates of cold-rolled Cu-Ni-Si-Co alloys were studied. The precipitate was (Ni, Co)Si and was in a strip shape. During aging, precipitation and coarsening of the (Ni, Co)Si precipitates were observed. In the early stage of aging, a significant number of fine (Ni, Co)Si precipitates were formed. These fine precipitates could not only have a better effect of precipitation strengthening, but also impeded the dislocation movement, thus increasing the dislocation density and improving the dislocation strengthening effect. However, the coarsening of the precipitates became dominant with increasing aging times. Therefore, the strengthening effect was weakened. The addition of 0.12% Mg promoted finer and more diffuse precipitates, which not only improving the tensile strength by 100-200 MPa, but also exhibiting a smaller effect on the electrical conductivity. However, further increases in Mg contents resulted in a significant decrease in electrical conductivity, with little change in the tensile strength. The optimum amount of added Mg was 0.12%, and the aging parameters were 300 °C and 20 min.
铜镍硅是高端引线框架铜合金的一个突出例子。在不降低电导率的情况下提高强度已成为一个突出的研究重点。析出相的演变对铜镍硅钴镁合金的强度和电导率有重大影响。本文研究了时效处理和添加镁对冷轧铜镍硅钴合金性能和析出相的影响。析出相为（镍，钴）硅，呈条状。时效过程中，观察到（镍，钴）硅析出相的析出和粗化。在时效初期，形成了大量细小的（镍，钴）硅析出相。这些细小析出相不仅具有更好的析出强化效果，还阻碍了位错运动，从而增加了位错密度，提高了位错强化效果。然而，随着时效时间的增加，析出相的粗化变得占主导地位。因此，强化效果减弱。添加0.12%的镁促进了更细小、更弥散的析出相，这不仅使抗拉强度提高了100 - 200MPa，而且对电导率的影响较小。然而，进一步增加镁含量会导致电导率显著下降，抗拉强度变化不大。添加镁的最佳含量为0.12%，时效参数为300℃和20分钟。
