New breakthrough in industrial application of high-performance thermal spray coating

       The key project "Industrialization of High-Performance Thermal Spray Coatings", undertaken by the Institute of Metal Research of the Chinese Academy of Sciences, has completed the stage goals and assessment indicators as planned (in advance). High-performance sealing coatings and thermal barrier coatings have been successfully applied to core power equipment such as turbo compressors and heavy ground gas turbines, and have completed industrial transformation. The adoption of this technology has promoted product upgrades and gained a place in international competition. The most advanced thermal barrier coating of nano-ZrO2 has been developed, which has been used in new power equipment.



Thermal spraying technology is to use various heat sources to heat metals or ceramics to a molten or semi-molten state, atomize and deposit them on the surface of the workpiece with the help of high-speed airflow to form a coating that is closely combined with the substrate. Because it has different composition and structure from the matrix, the matrix obtains special properties to meet the higher performance requirements of the workpiece. The coating generally consists of an adhesive primer and a topcoat. The bottom layer is prepared with alloy powder which can resist high temperature oxidation, improve the thermal matching between the surface layer and the substrate, and improve the bonding strength of the coating, while the surface layer is a metal, alloy or non-metal material according to the performance requirements of the component. With the development of science and technology, new spray materials and new spray technologies have emerged, and new special-purpose high-performance thermal spray coatings such as sealing coatings, thermal barrier coatings, and self-lubricating coatings have emerged. Thermal spraying technology is widely used in aerospace, metallurgy, textile, automobile, printing, petrochemical and other industries. The proportion of a country's thermal spraying output value in the gross national economic output (GDP) is an important symbol of whether the country's thermal spraying is developed or not. The total output value of thermal spraying in the United States accounts for 0.36‰ of GDP, Japan is 0.23‰, while my country only accounts for 0.039‰, which is only 11% of the United States and 17% of Japan. This shows that China's thermal spraying is still in the development stage, far from reaching maturity and saturation. It can be seen that thermal spraying has a huge market in China and has great development space.



This project is dedicated to the industrial application and industrialization of new high-performance sealing coatings and thermal barrier coatings on cutting-edge core power equipment such as turbo compressors and ground gas turbines. After a year and a half of hard work, breakthroughs have been made in the industrial application of high-performance thermal spray coatings, and applications in some fields have been industrialized. In order to meet the requirements of industrialization, infrastructure construction was carried out. The Institute of Metal Research, Chinese Academy of Sciences invested 11 million yuan to build a 1500m2 "thermal spraying research and development base" in Shenyang Hunnan High-tech Industrial Development Zone, which was completed and put into use in October 2007. On the basis of the original equipment conditions, advanced preparation equipment such as supersonic flame spraying and special testing instruments are newly added. The newly built "R&D base" has complete functions, reasonable layout and high degree of production automation, which meets the needs of large-scale production of this project.



The sealing coating technology is applied to the turbo compressor for the first time in my country



Although the G series turbo compressor newly developed by Shenyang Blower Group Co., Ltd., a leading enterprise in my country's compressor industry, is the most advanced product in China, it has not yet adopted the key technology of gas path sealing, which has been widely used in foreign countries. There is a big gap in performance compared with foreign countries. The Institute of Metals has cooperated with the company to overcome this technical problem. After repeated application tests, it has developed a high-performance sealing coating suitable for turbo compressors. It has produced several (sets) of compressor spindles, rotor components, volutes, Parts such as rings are coated and used in compressors. After the G series turbo compressor adopts this technology, the efficiency is significantly improved, the energy consumption is effectively reduced, and the performance of the whole machine is significantly improved, thereby enhancing the international competitiveness. Moreover, the high-performance sealing coating is applied to another cutting-edge aerospace power equipment, which has been mass-produced, and the Metal Institute has been designated as the designated production unit of sealing coating by the user department. Turbocompressors and cutting-edge engines are iconic equipment representing a country's manufacturing level. The successful application of sealing coating technology will produce a strong technical radiation effect and promote the popularization and application of this technology.



High Performance Thermal Barrier Coating Applied to Surface Gas Turbine Hot End Components



Ground-based heavy-duty gas turbines have gradually become the world's main power generation equipment and important military power equipment in the 21st century, and are recognized as a new generation of power generation equipment in the world. At present, domestic ground gas turbines are imported from abroad, and there are 130 units (sets). The protection technology of its hot end components is the core technology of gas turbine production and repair, which is kept secret from the outside world. The protection and repair of hot end components is monopolized by foreign companies. The development of high-temperature resistant and long-life thermal barrier coatings that fully meet the requirements of gas turbine use has become a new topic for the development of my country's independent gas turbine business and the localization of imported spare parts. The Institute of Metals and AVIC Shixin Gas Turbine Co., Ltd. Shenyang Branch jointly developed ZrO2 thermal barrier coatings, which are applied to MS6001, MS6581, 251B, 4E, MS5000 and other types of flame tubes, transition sections, blades, guard rings and other components. About 30 sets (sets) of gas turbine coating products are produced. The user's evaluation of its quality is that "no matter the spraying material or the coating performance, it meets the requirements for use, the coating performance is equivalent to the imported product, and the use effect is good".



This project independently developed and produced thermal barrier coatings for hot-end components, which not only achieved considerable economic benefits, but also had important social benefits, ended the situation of relying on foreign countries for core technologies, and improved international market competitiveness. On the basis of the application of conventional structure ZrO2 thermal barrier coating, a new type of higher performance nano ZrO2 thermal barrier coating has also been developed to meet the development requirements of high thrust-to-weight ratio cutting-edge power equipment. The microhardness and bonding strength of the nano-ZrO2 coating are 1.5 times that of the conventional ZrO2 coating, the thermal shock resistance is increased by about 2-3 times, and the thermal insulation effect is increased by more than 50 °C. The research and development of nano-ZrO2 thermal barrier coating has passed the "process review" organized by the user department and has been put into production. This innovation has reached the international advanced level and opened up a new way for the development of thermal barrier coatings.



Contribute to industry and regional economic and technological development



In order to promote the development of this technology in the Liaoning region and make it a platform for promotion and exchange, personnel training and technical services, in August 2006, the Liaoning Provincial Department of Science and Technology, relying on the Institute of Metals, established the "Liaoning Provincial High-performance Thermal Spray Coating Engineering Technology Research Center". ". The center transferred high-performance thermal spray coating technology to Shenyang Li Heating Energy Gas Turbine Equipment Parts Co., Ltd. in May 2007, and the technology transfer fee was 3.1 million yuan. The company uses this technology to realize its own production of gas turbine coating products, reducing product costs, improving product performance and enhancing market competitiveness. In October 2007, it cooperated with Tieling Yongxing Thermal Spray Co., Ltd. to establish the "Tieling Thermal Spray Test Base of the Institute of Metal Research, Chinese Academy of Sciences". Through the above-mentioned technology transfer and technical cooperation, the technology can be radiated to a wider application field, which has a positive effect on the development of regional economy and technology, and achieved good results.



At present, the project is progressing smoothly, exceeding the target of the planned completion stage. It is expected that after another year and a half of hard work, it is expected to complete the overall goal of the project with high quality and high level, that is to build a domestic first-class high-performance thermal spray coating production base, realize the industrialization of high-performance thermal spray coating, and achieve an annual sales income of over 5,000 yuan. million. At the same time, through the application of high-tech in high-end equipment, it can promote the upgrading of enterprise products, improve the competitiveness of domestic and foreign markets, bring huge economic and social benefits to the enterprise, and play an active role in revitalizing the old industrial base in Northeast China.