What are the main characteristics of ceramic coating materials

       Ceramics usually refer to a general term for various oxides (mainly metal oxides), carbides, borides, silicides, and nitrides. The ceramics used for thermal spraying refer to crystalline ceramics, which are called engineering ceramics because they are mainly used in various engineering projects.

    Generally speaking, any material that can be in a molten state or plastic state by heating can be used as a coating material for thermal spraying. In addition to metallic materials, ceramics can also be used for thermally sprayed anti-corrosion coatings. The ceramic materials commonly used in thermal spraying are mainly oxide ceramic materials such as AI2O3, TiO2, Cr2O3, ZrO2, and non-oxide ceramics such as carbides are usually prepared into metal matrix ceramic composite materials by using metal alloys as binders. Due to the brittleness and poor oxidation resistance of nitrides, it is rarely used.

    Ceramic materials generally have the characteristics of high hardness, high melting point, good thermal stability and chemical stability. When used as a coating, they can effectively improve the wear resistance, high temperature resistance, high temperature oxidation resistance, thermal shock resistance, corrosion resistance, etc. performance. Some of these superior properties can be obtained through the correct selection of materials.

    Ceramic materials generally have a higher melting point. In order to make them fully melt and prepare their coatings, a higher temperature heat source is generally required. Therefore, the coatings of these materials are commonly used by plasma spraying, especially the high-efficiency supersonic plasma spraying technology can prepare high-quality and high-performance ceramic coatings. However, the combustion flame used for spraying metal materials, such as the oxygen-acetylene flame, is difficult to completely melt due to the low temperature, and the prepared coating particles have weak bonding, which is generally not suitable for spraying ceramic coatings.

    Due to the high price of ceramic materials and the complex spraying process, the application range of ceramic coatings is limited. Only those occasions with high corrosion resistance requirements or occasions requiring high wear resistance and heat resistance, and cannot be replaced by other coating methods. Consider using a ceramic coating. The ceramic materials used in thermal spraying are supplied in the form of powder. The particle size and shape of the powder have a great influence on the powder feeding during spraying. Specially produced powders are required for thermal spraying.

    The particle size range of thermal spray ceramic powder varies according to its application, and the commonly used powder particle sizes are μm 10μm ~44μm, 10μm ~52μm, 5μm ~25μm and 30μm ~74. μm. Domestic powder manufacturers generally sieve according to the requirements of users, and provide powders with the required particle size range.