The precipitation behavior and strengthening effects of the Cu-0.42Cr-0.16Co alloy aged at 450 °C was investigated using atom-probe tomography, transmission electron microscopy, and hardness and electrical conductivity measurements. The results showed that the fine FCC Cr-rich precipitates with a cube-on-cube orientation relationship (OR) were formed by Cr and Co enrichment at the early aging stage, semi-coherent with the Cu matrix. The OR transformation of the FCC Cr-rich precipitates from the cube-on-cube OR to the OR of ${\left(\overline{2}20\right)}_{\mathrm{Cu}}$//${\left(\overline{2}20\right)}_{\mathrm{Cr}}$, [112]_Cu//[110]_Cr occurred with prolonging the aging time. The OR transformation decreased the mismatch degree along the ${\left[11\overline{1}\right]}_{\mathrm{Cu}}$ and [112]_Cu crystallographic directions and produced a strain difference along different crystallographic directions. Thus, some ellipsoid precipitates were formed in the Cu-Cr-Co alloy during aging. In the peak-aged stage (aged for 8 h), the aging strengthening of the Cu-Cr-Co alloy was mainly attributed to the precipitation of the FCC Cr-rich particles, and the strengthening was controlled by the Orowan mechanism. The peak-aged alloy exhibited a larger size of precipitates than the alloy aged for 4 h, inducing a stronger precipitation strengthening effect (∼153 MPa).

使用原子探针断层扫描、透射电子显微镜以及硬度和电导率测量研究了 Cu-0.42Cr-0.16Co 合金在 450 °C 时效时的析出行为和强化效果。结果表明，在早期时效阶段，Cr 和 Co 富集形成具有立方对立方取向关系 (OR) 的精细 FCC 富 Cr 析出物，与 Cu 基体半共格。FCC 富铬析出物的 OR 转化从 cube-on-cube OR 到 OR${\left(\overline{\mathrm{2个}}20\right)}_{\mathrm{铜}}$//${\left(\overline{\mathrm{2个}}20\right)}_{\mathrm{铬}}$, [112] _Cu //[110] _Cr随着时效时间的延长而产生。OR 变换降低了错配度${\left[11\overline{\mathrm{1个}}\right]}_{\mathrm{铜}}$和 [112] _Cu结晶方向，并沿不同的结晶方向产生应变差异。因此，在时效过程中，Cu-Cr-Co 合金中形成了一些椭圆形沉淀物。在峰值时效阶段（时效8 h），Cu-Cr-Co合金的时效强化主要归因于FCC富Cr颗粒的析出，强化受控于Orowan机制。峰值时效合金比时效 4 小时的合金表现出更大尺寸的析出物，导致更强的析出强化效应（~153 MPa）。