The global thermal spray coatings market was valued at USD 10.1 billion in 2019 and is expected to grow at a compound annual growth rate of 3.9% from 2020 to 2027. Carbide coatings form an essential segment of this market and provide cost-effective and environmental friendly tribological solutions for applications in aerospace, industrial gas turbine, automotive, printing, oil and gas, steel, and pulp and paper industries. Almost 23% of the world’s total energy consumption originates from tribological contacts. Thermal spray WC-Co coatings provide excellent wear resistance for industrial applications in sliding and rolling contacts. Some of these applications in abrasive, sliding and erosive conditions include sink rolls in zinc pots, conveyor screws, pump housings, impeller shafts, aircraft flap tracks, cam followers and expansion joints. These coatings are considered as a replacement of the hazardous chrome plating for tribological applications. The microstructure of thermal spray coatings is however complex, and the wear mechanisms and wear rates vary significantly when compared to cemented WC-Co carbides or vapour deposition WC coatings. This paper provides an expert review of the tribological considerations that dictate the sliding wear performance of thermal spray WC-Co coatings. Structure–property relationships and failure modes are discussed to grasp the design aspects of WC-Co coatings for tribological applications. Recent developments of suspension sprayed nanocomposite coatings are compared with conventional coatings in terms of performance and failure mechanisms. The dependency of coating microstructure, binder material, carbide size, fracture toughness, post-treatment and hardness on sliding wear performance and test methodology is discussed. Semiempirical mathematical models of wear rate related to the influence of tribological test conditions and coating characteristics are analysed for sliding contacts. Finally, advances for numerical modelling of sliding wear rate are discussed.

2019年，全球热喷涂涂料市场价值101亿美元，预计从2020年到2027年，复合年增长率为3.9％。硬质合金涂料是该市场的重要组成部分，可提供经济高效且环保的产品适用于航空航天，工业燃气轮机，汽车，印刷，石油和天然气，钢铁以及纸浆和造纸行业的摩擦学解决方案。世界总能耗中近23％来自摩擦接触。WC-Co热喷涂涂层为滑动和滚动接触的工业应用提供了出色的耐磨性。这些在磨蚀，滑动和侵蚀性条件下的应用包括锌罐中的沉辊，输送机螺杆，泵壳，叶轮轴，飞机襟翼轨道，凸轮从动件和伸缩缝。这些涂层被认为是摩擦学应用中有害铬镀层的替代品。但是，热喷涂涂层的微观结构很复杂，与硬质合金WC-Co碳化物或气相沉积WC涂层相比，磨损机理和磨损率有很大差异。本文提供了摩擦学因素的专家综述，这些因素决定了热喷涂WC-Co涂层的滑动磨损性能。讨论了结构-特性关系和破坏模式，以掌握摩擦学应用中WC-Co涂层的设计方面。就性能和破坏机理而言，将悬浮喷涂的纳米复合涂料的最新发展与常规涂料进行了比较。涂层微观结构，粘合剂材料，碳化物尺寸，断裂韧性，讨论了后处理和硬度对滑动磨损性能及测试方法的影响。分析了与摩擦测试条件和涂层特性有关的磨损率的半经验数学模型。最后，讨论了滑动磨损率数值建模的进展。