Interdiffusion and chemical reactions contribute to tool wear in metal machining. Increased understanding of these processes, through characterisation of worn tools, can facilitate design of more resilient materials through chemical and diffusional passivation. However, the unknown reaction conditions, the large number of elements, and the formation of interspersed phases makes for a complex analysis. Here, we demonstrate the use of scanning transmission electron microscopy and energy dispersive X-ray spectroscopy for characterising the interaction layer between a titanium alloy and a cemented carbide tool. Principal component analysis is used to find chemical correlations and help separate signals from embedded phases. Crucially, we evaluate the required X-ray count statistics from simulated spectrum images and theory prior to the experiment. We find no indications of intermediate phases between the original WC and the metallic W interaction layer. Furthermore, we find enrichment of minor constituents in the titanium alloy closest to the tool which alter the solubility of out-diffusing species, suggesting strong interrelations between the diffusion processes.

中文翻译：

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使用主成分分析辅助的 STEM-EDS 表征磨损的 WC 工具

相互扩散和化学反应会导致金属加工中的刀具磨损。通过对磨损工具的表征，加深对这些过程的了解，可以通过化学和扩散钝化促进更具弹性的材料的设计。然而，未知的反应条件、大量元素以及散布相的形成使得分析变得复杂。在这里，我们展示了使用扫描透射电子显微镜和能量色散 X 射线光谱来表征钛合金和硬质合金工具之间的相互作用层。主成分分析用于查找化学相关性并帮助从嵌入的相位中分离信号。至关重要的是，我们在实验之前根据模拟光谱图像和理论评估所需的 X 射线计数统计数据。我们没有发现原始 WC 和金属 W 相互作用层之间存在中间相的迹象。此外，我们发现最靠近工具的钛合金中微量成分的富集改变了外扩散物质的溶解度，表明扩散过程之间存在很强的相互关系。