Nano-crystalline (nc) Cu with Cr₂O₃ dispersoid (~4 vol.%) was successfully made by reactive-milling at 210 K with a mixture of pure Cu, Cu₂O, and Cr powder. The vacuum hot pressing (HP) was performed at 1123 K and 50 MPa for 2h to consolidate the milled powder for further analysis. TEM (Transmission Electron Microscopy) work revealed that the HPed materials were comprised with a mixture of the nc-Cu and a homogeneous distribution of Cr₂O₃ dispersoids. The microstructure and Vickers hardness of the as-milled powder and the HPed materials were characterized by standard metallographic techniques. The grain size of the Cu was measured using Scherrer’s formula (XRD) and TEM observation; the Cr₂O₃ dispersoid size was estimated from the HADDF (High Angle Annular Dark Field) images and element mapping by STEM-EDS (Scanning Transmission Electron Microscopy-Energy Dispersive Spectroscopy) works. The formation kinetics and coarsening of the Cr₂O₃ dispersoids in Cu matrix were discussed based on the calculations with thermodynamic parameters in comparison with those of Al₂O₃.

中文翻译：

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低温研磨合成Cr2O3分散Cu的形成动力学

通过在210 K下用纯Cu，Cu ₂ O和Cr粉末的混合物进行反应研磨，成功制备了具有Cr ₂ O ₃弥散体（〜4％（体积））的纳米晶体（nc）Cu 。在1123 K和50 MPa下进行真空热压（HP）2小时，以固结磨碎的粉末，以进行进一步分析。TEM（透射电子显微镜）工作表明，HPed材料包含nc-Cu和Cr ₂ O ₃分散质均匀分布的混合物。通过标准金相技术表征研磨后的粉末和HPed材料的显微组织和维氏硬度。使用Scherrer公式（XRD）和TEM观察法测量Cu的晶粒尺寸；铬₂根据HADDF（高角度环形暗场）图像和STEM-EDS（扫描透射电子显微镜-能量色散光谱）工作的元素映射，估算出O ₃分散体的大小。基于热力学参数的计算和Al ₂ O _3的比较，讨论了Cu基体中Cr ₂ O ₃弥散体的形成动力学和粗化。