Fan Kunyang, Jiang Wenhuang, Luzin Vladimir, Gong Taimin, Feng Wei, Ruiz-Hervias Jesus, Yao Pingping
School of Mechanical Engineering, Chengdu University, Chengdu 610106, China.
Sichuan Province Engineering Technology Research Center of Powder Metallurgy, Chengdu University, Chengdu 610106, China.
Materials (Basel). 2022 Aug 11;15(16):5537. doi: 10.3390/ma15165537.
Cermet coatings deposited using high-velocity oxy-fuel (HVOF) are widely used due to their excellent wear and corrosion resistance. The new agglomeration-rapid sintering method is an excellent candidate for the preparation of WC-Co-Cr feedstock powders. In this study, four different WC-10Co-4Cr feedstock powders containing WC particles of different sizes were prepared by the new agglomeration-rapid sintering method and deposited on steel substrates using the HVOF technique. The microstructures and mechanical properties of the coatings were investigated using scanning electron microscopy, X-ray diffraction, nanoindentation, and Vickers indentation. The through-thickness residual stress profiles of the coatings and substrate materials were determined using neutron diffraction. We found that the microstructures and mechanical properties of the coatings were strongly dependent on the WC particle size. Decarburization and anisotropic mechanical behaviors were exhibited in the coatings, especially in the nanostructured coating. The coatings containing nano- and medium-sized WC particles were dense and uniform, with a high Young's modulus and hardness and the highest fracture toughness among the four coatings. As the WC particle size increased, the compressive stress in the coating increased considerably. Knowledge of these relationships enables the optimization of feedstock powder design to achieve superior mechanical performance of coatings in the future.
采用高速氧燃料（HVOF）沉积的金属陶瓷涂层因其优异的耐磨性和耐腐蚀性而被广泛应用。新的团聚-快速烧结法是制备WC-Co-Cr原料粉末的理想方法。在本研究中，通过新的团聚-快速烧结法制备了四种不同的WC-10Co-4Cr原料粉末，这些粉末含有不同尺寸的WC颗粒，并使用HVOF技术沉积在钢基体上。采用扫描电子显微镜、X射线衍射、纳米压痕和维氏压痕对涂层的微观结构和力学性能进行了研究。使用中子衍射测定了涂层和基体材料的贯穿厚度残余应力分布。我们发现涂层的微观结构和力学性能强烈依赖于WC颗粒尺寸。涂层中表现出脱碳和各向异性力学行为，特别是在纳米结构涂层中。含有纳米和中等尺寸WC颗粒的涂层致密且均匀，并具有高杨氏模量和硬度，以及四种涂层中最高的断裂韧性。随着WC颗粒尺寸的增加，涂层中的压应力显著增加。了解这些关系有助于优化原料粉末设计，以便在未来实现涂层卓越的力学性能。
