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利用X射线衍射仪、金相显微镜和电子探针考察了(Ti、W)C 固溶体的形成过程。用粉末反应动力学方程对实验结果进行了处理并与观察固溶体形成过程中微观组织结构的变化特征相结合的方法分析了固溶体形成的扩散机制。结果表明:(Ti、W)C 固溶体在不同温度范围内的形成机理是不同的:低温碳化时(t<1850℃),固溶体的形成是以 TiC 和 WC 之间的体积扩散为特征的“错球模型”,其表观互扩散激活能为431kJ/mol,而高温碳化时(t≥1850℃),固溶体的形成是以 TiC 和 WC 之间的表面扩散为特征的“同心球模型”,其表观互扩散激活能为87kJ/mol,从而深化了对(Ti、W)C 固溶体形成过程的认识。
The formation of (Ti, W) C solid solution was investigated by X-ray diffraction, optical microscope and electron probe. The powder reaction kinetics equation was used to deal with the experimental results and to analyze the diffusion mechanism of solid solution formation in combination with the observation of the change characteristics of microstructure during solid solution formation. The results show that the formation mechanism of (Ti, W) C solid solution is different in different temperature range. In low temperature carbonization (t <1850 ℃), the formation of solid solution is characterized by the volume diffusion between TiC and WC Spherical model “, the apparent activation energy of interdiffusion is 431kJ / mol, and the formation of solid solution is the” concentric sphere model "characterized by surface diffusion between TiC and WC at high temperature carbonization (t≥1850 ℃) The activation energy of apparent interdiffusion is 87 kJ / mol, which deepens the understanding of the formation of (Ti, W) C solid solution.