To overcome the issue of coarse grains and low synthetic content of in-situ synthesized WC due to its low nucleation drive, TiC was used as nucleating agent to promote the nucleation of WC during laser cladding. The interfacial energy and electronic structure of the heterogeneous nucleation interface were investigated by first-principles calculations. The calculated results show that TiC(111) surfaces are good heterogeneous nucleation interfaces for WC because they can form a co-lattice interface with a lattice mismatch of 4.6 % and have a high adhesion work (Wad) and a low interfacial energy (γ), e.g., the W-WC(0001)/C-TiC(111)-HCP1 interface exhibits a Wad of 9.78 J m−2 and a γ of 1.86 ∼ 1.89 J m−2 and the W-WC(0001)/Ti-TiC(111)-HCP1 interface exhibits a Wad of 5.38 J m-2 and a γ of 1.02 ∼ 1.62 J m−2. The experimental results confirm that TiC is an effective nucleating agent to promote the nucleation of WC. The content of the WC increases from 34.96 % to 66.80 % and the grain size of the WC is refined from 13.37 nm to 3.53 nm after the pre-addition of 2 wt% TiC.

中文翻译：

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以 TiC 为非均相成核位点的原位合成 WC-Ni 涂层的研究：第一性原理计算和实验研究


为了克服原位合成 WC 由于成核驱动低而导致晶粒粗和合成含量低的问题，使用 TiC 作为成核剂，在激光熔覆过程中促进 WC 的成核。通过第一性原理计算研究了异质成核界面的界面能和电子结构。计算结果表明，TiC（111） 表面是 WC 的良好异相成核界面，因为它们可以形成晶格失配为 4.6 % 的共晶格界面，并且具有高粘附功 （Wad） 和低界面能 （γ），例如，W-WC（0001）/C-TiC（111）-HCP1 界面的 Wad 为 9.78 J m-2，γ为 1.86 ∼ 1.89 J m-2，W-WC（0001）/Ti-TiC（111）-HCP1 界面表现出Wad 为 5.38 J m-2 和 1.02 ∼ 1.62 J m-2 γ。实验结果证实，TiC 是一种促进 WC 成核的有效成核剂。WC 的含量从 34.96 % 增加到 66.80 %，预添加 2 wt% TiC 后，WC 的晶粒尺寸从 13.37 nm 细化到 3.53 nm。