The semi-solid sintering of a novel Ti6Al4V/CoCrMo biomedical composite was investigated for the first time by semi-in situ X-ray computed microtomography. Composite was fabricated by dry mixing 15 vol% CoCrMo reinforcing particles with Ti6Al4V particles as matrix. The mixture was poured into a 1 mm diameter quartz capillary. 3D images of the same sample were acquired before and after sintering at different temperatures between 1050 and 1130 °C. Qualitative and quantitative analysis of the 3D images was carried out to observe the evolution of the microstructure. Formation and evolution with temperature of eutectic phase were monitored. It was found that the eutectic reaction started between Ti6Al4V and CoCrMo particles at 1050 °C, first in the contact area and then the liquid of eutectic phase was distributed over the surface of Ti6Al4V particles and filled the interparticle pores. Size and sphericity of Ti6Al4V and CoCrMo particles diminished as the volume fraction of eutectic phase increased. After sintering at 1130 °C most of CoCrMo particles disappeared because they react with Ti6Al4V to form the Ti 2 Co phase. Porosity is reduced 15% mainly by reducing the smaller pores that can be filled by the eutectic phase. Thus, it was concluded that semi-in situ X-ray computed microtomography is an effective tool to investigate the semi-solid state sintering and to analyze the microstructure evolution and densification mechanisms.

中文翻译：

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半固态烧结制备的 Ti6Al4V/CoCrMo 生物医学复合材料的 X 射线计算机显微成像表征

首次通过半原位 X 射线计算机显微成像研究了新型 Ti6Al4V/CoCrMo 生物医学复合材料的半固态烧结。复合材料是通过将 15 vol% CoCrMo 增强颗粒与 Ti6Al4V 颗粒作为基体干混合而制成的。将混合物倒入直径为 1 毫米的石英毛细管中。在 1050 到 1130 °C 之间的不同温度下，在烧结前后获取相同样品的 3D 图像。对 3D 图像进行定性和定量分析以观察微观结构的演变。监测随共晶相温度的形成和演变。发现 Ti6Al4V 和 CoCrMo 颗粒在 1050 °C 开始发生共晶反应，首先在接触区域，然后共晶相的液体分布在 Ti6Al4V 颗粒表面并填充颗粒间孔隙。Ti6Al4V 和 CoCrMo 颗粒的尺寸和球形度随着共晶相体积分数的增加而减小。在 1130 °C 下烧结后，大部分 CoCrMo 颗粒消失，因为它们与 Ti6Al4V 反应形成 Ti 2 Co 相。孔隙率降低 15% 主要是通过减少共晶相可以填充的较小孔隙。因此，得出的结论是，半原位 X 射线计算机显微断层扫描是研究半固态烧结和分析微观结构演变和致密化机制的有效工具。在 1130 °C 下烧结后，大部分 CoCrMo 颗粒消失，因为它们与 Ti6Al4V 反应形成 Ti 2 Co 相。孔隙率降低 15% 主要是通过减少共晶相可以填充的较小孔隙。因此，得出的结论是，半原位 X 射线计算机显微断层扫描是研究半固态烧结和分析微观结构演变和致密化机制的有效工具。在 1130 °C 下烧结后，大部分 CoCrMo 颗粒消失，因为它们与 Ti6Al4V 反应形成 Ti 2 Co 相。孔隙率降低 15% 主要是通过减少共晶相可以填充的较小孔隙。因此，得出的结论是，半原位 X 射线计算机显微断层扫描是研究半固态烧结和分析微观结构演变和致密化机制的有效工具。