Key breakthrough of plasma spraying technology in surface treatment of special materials

Key breakthrough of plasma spraying technology in surface treatment of special materials

Plasma spraying technology has achieved the following key breakthroughs in surface treatment of special materials:

Preparation of coatings for complex material systems

Multiple materials with different properties, such as metals, ceramics, polymers, etc., can be accurately mixed and sprayed into coatings to prepare composite material coatings with comprehensive performance. For example, spraying ceramic metal composite coatings on metal substrates combines the high hardness, high temperature resistance, and wear resistance of ceramics with the toughness and good electrical and thermal conductivity of metals, meeting the complex performance requirements of coatings for high-temperature components of aircraft engines.

Nanomaterials can be successfully introduced into coatings to prepare nanostructured coatings. The unique properties of nanomaterials, such as high specific surface area and quantum size effect, enhance the mechanical, tribological, and corrosion resistance properties of coatings. For example, the hardness and wear resistance of nano alumina coatings are several times higher than traditional alumina coatings, and they are widely used in tool surface treatment.

Enhance the bonding strength between coatings and special material substrates

By special pretreatment of the substrate surface, such as using ion beam assisted deposition technology to bombard the substrate surface, clean the surface and introduce lattice defects, increase surface activity, and form stronger chemical bonds and mechanical bite between the coating and the substrate, thus improving the bonding strength. This method effectively solves the problem of coating detachment in surface treatment of difficult to bond materials such as titanium alloys.

We have developed a new type of transition layer material and structure, which introduces a transition layer with gradually changing composition and structure between the coating and the substrate, alleviating stress concentration caused by differences in thermal expansion coefficients between the two. For example, setting up a metal ceramic gradient transition layer between the ceramic coating and the metal substrate greatly improves the bonding stability of the coating in high-temperature environments, which has been widely used in the field of aerospace thermal barrier coatings.

Accurately control the microstructure and properties of coatings

By utilizing advanced plasma spraying equipment and process control technology, such as real-time monitoring of plasma parameters and powder flight status, precise adjustment of spraying process parameters, and precise control of coating microstructure. The microstructure parameters such as porosity, grain size, and phase composition of the coating can be controlled to achieve ideal performance. For example, by adjusting process parameters to prepare thermal barrier coatings with controllable porosity, the thermal shock resistance of the coating is improved while ensuring thermal insulation performance.

By using computer simulation and numerical calculation techniques, the plasma spraying process is simulated and analyzed to gain a deeper understanding of the coating formation mechanism and microstructure evolution laws, providing theoretical guidance for optimizing process parameters and designing coating structures. By simulating the melting, flight, and deposition processes of powders under different process conditions, the performance of coatings was predicted, reducing the number of trial and error experiments and improving the success rate and quality stability of coating preparation.

Expand applications in special service environments

Enable the coating to maintain good performance in special service environments such as extreme temperatures, strong corrosion, and high radiation. For example, the development of coating systems that are resistant to high temperatures, oxidation, and thermal shock has been applied to high-temperature components such as aircraft engine combustion chambers, effectively improving the service life and reliability of the components; Developed coatings resistant to strong corrosive media for equipment protection in fields such as marine engineering and chemical engineering, solving the corrosion problem of materials in harsh corrosive environments.

We have achieved uniform coating preparation on the surfaces of some special materials and special shaped components. For example, high-precision optical coatings are prepared on the surface of optical components with complex curved surfaces. By optimizing spray trajectory planning and process parameters, the thickness uniformity and optical performance consistency of the coatings are ensured; The successful preparation of protective coatings on the surface of new materials such as carbon fiber composites meets the application needs of these materials in aerospace, new energy and other fields.