Owing to their high hardness, fracture toughness and oxidation resistance, tungsten carbide (WC) coatings are extensively deposited on parts that operate in demanding applications, necessitating wear, erosion, and corrosion resistance. The application of thick and hard WC coatings has an inevitable effect on the original dimensions of the parts, affecting the geometrical tolerances and surface roughness. The capability of achieving a sub-micron surface finish and adhere to tight geometrical tolerances accurately and repeatably is an important requirement, particularly with components that operate in high-precision sliding motion. Meeting such requirements through conventional surface finishing methods, however, can be challenging due to the superior mechanical and tribological properties of WC coatings. A brief review into the synthesis techniques of cemented and binderless WC coatings is presented together with a comprehensive review into the available techniques which are used to surface finish WC-based coatings with reference to their fundamental mechanisms and capabilities to process parts with intricate and internal features. The binderless WC/W coating considered in this work is deposited through chemical vapour deposition (CVD) and unlike traditional cemented carbide coatings, it has a homogenous coating structure. This distinctive characteristic has the potential of eliminating key issues commonly encountered with machining and finishing of WC-based coatings. Here, six contact and non-contact surface finishing techniques, include diamond turning, precision grinding, superfinishing, vibratory polishing, electrical discharge machining, and electropolishing are discussed along with their current use in industry and limitations. Key challenges in the field are highlighted and potential directions for future investigation, particularly on binderless WC coatings, are proposed herein.

中文翻译：

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碳化钨硬质复合涂层的精密加工和表面处理的最新进展

由于它们的高硬度，断裂韧性和抗氧化性，碳化钨（WC）涂层广泛沉积在要求苛刻的应用中运行的零件上，因此需要耐磨，耐腐蚀和耐腐蚀。厚而硬的WC涂层的应用对零件的原始尺寸产生不可避免的影响，影响几何公差和表面粗糙度。达到亚微米表面光洁度并精确且可重复地遵守严格的几何公差的能力是一项重要要求，尤其是对于以高精度滑动运动运行的组件而言。但是，由于WC涂层具有出色的机械和摩擦学性能，通过常规的表面处理方法满足这些要求可能是具有挑战性的。简要介绍了水泥和无粘结剂WC涂层的合成技术，并综合了可用于对基于WC的涂料进行表面处理的可用技术的全面综述，并参考了它们处理具有复杂和内部特征的零件的基本机理和能力。 。这项工作中考虑的无粘结剂WC / W涂层是通过化学气相沉积（CVD）进行沉积的，与传统的硬质合金涂层不同，它具有均匀的涂层结构。这种独特的特性有可能消除WC基涂层的机加工和精加工中经常遇到的关键问题。这里有六种接触和非接触表面精加工技术，包括金刚石车削，精密研磨，超精加工，振动抛光，放电加工，讨论了电抛光和电抛光及其在工业中的当前用途和局限性。突出了该领域中的关键挑战，并在此提出了未来研究的潜在方向，特别是在无粘结剂的WC涂层方面。