【摘要】 采用大气熔炼制备了Cu-Ni-Co-Si-Mg-xCr（x=0%、0.15%、0.32%、0.4%）4种合金，热挤压后对其在950、980和1010℃进行1.5 h的固溶处理。采用能谱分析铸态合金中Cr的存在形式，分析不同Cr含量对合金组织性能的影响，采用维氏硬度仪和电导仪测试不同状态下合金的硬度及导电率。结果表明：Cr与Co、Si元素偏聚产生Co₆Cr₈Si₅金属间化合物，且占比随着Cr含量的增加而增加。随着固溶温度的升高，合金晶粒中未回溶第二相和Co₆Cr₈Si₅金属间化合物逐渐减少，晶粒尺寸逐渐增大，且Co₆Cr₈Si₅金属间化合物由于钉扎作用有效抑制合金晶粒的长大。固溶处理后，元素及第二相粒子回溶降低弥散强化效果，提升固溶强化效果，此消彼长导致硬度变化无规律，导电率整体下降。Cu-Ni-Co-Si-Mg-xCr（x=0%、0.15%、0.32%、0.4%）合金经980和1010℃固溶处理1.5 h,可使晶粒尺寸无剧烈长大的条件下提高合金的过饱和度，增加后续时效析出驱动力。更多还原

【Abstract】 Four alloys, Cu-Ni-Co-Si-Mg-xCr（x=0%, 0.15%, 0.32%, 0.4%）, were prepared by atmospheric melting, and after hot extrusion, they were subjected to solution treatment at 950 ℃, 980 ℃ and 1010 ℃ for 1.5 h. The existence form of Cr in the as-cast alloys was analyzed by energy spectrum, the effect of different Cr content on microstructure and properties of the alloys was examined, and the hardness and conductivity of the alloys in different states were tested by Vickers hardness tester and electrical conductivity tester. The results show that Cr and Co, Si elements tend to aggregate to form Co₆Cr₈Si₅ intermetallic compounds, and the proportion increases with the increase of Cr content. As the solution treatment temperature increases, the undissolved second phase and Co₆Cr₈Si₅ intermetallic compounds in the alloy grains gradually decrease, and the grain size gradually increases. Moreover, the Co₆Cr₈Si₅ intermetallic compounds effectively inhibit the growth of the alloy grains due to the pinning effect. After solution treatment, the re-dissolution of elements and second phase particles reduces the dispersion strengthening effect and enhances the solid solution strengthening effect. This fluctuation leads to irregular changes in hardness, and electrical conductivity decreases as a whole. After solution treatment at 980 ℃ and 1010 ℃ for 1.5 h, the grain size of the Cu-Ni-Co-Si-Mg-xCr（x=0%, 0.15%, 0.32%, 0.4%）alloys does not grow dramatically, which can increase the supersaturation of the alloys and increase the subsequent aging precipitation driving force.更多还原