Wind turbine-resistant wear coating with high content

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Wind turbine blades are the key components of wind power generators, accounting for approximately 20% of their total cost. Currently, epoxy fiberglass or unsaturated polyester fiberglass is commonly used as the main material for manufacturing these blades, and both of these materials possess excellent mechanical properties. According to the design requirements, the service life of the blades should be 20 years. Currently, wind farms in China are mainly land-based and are located in desert areas and regions prone to sandstorms. These areas are characterized by severe sandstorms and long daylight hours, and as the global climate becomes more severe, the environmental conditions there are becoming increasingly harsh. The atmospheric conditions in China’s coastal areas, such as high temperatures, high humidity, high salt fog, and long daylight hours, are the main environmental factors faced by offshore wind power equipment. Therefore, the external factors that cause damage to the blades during normal operation are: first, high levels of ultraviolet radiation; second, the erosion of the substrate by wind and sand, dust, and salt spray. Since the linear velocity at the tip of the blade can reach 80 meters per second during normal operation, in land-based wind turbines, the sand particles present in the wind exert strong impacts on the blade surface ； High-salt-fog gas or raindrops can accelerate the corrosion of coatings on offshore wind turbine blades. Therefore, erosion of the substrate by wind and sand, dust, and salt spray is more severe; if the coating on the blades does not have good resistance to sand erosion or salt spray, it is difficult for the protective coating to last 20 years. Therefore, how to minimize external erosion will be the key factor determining the actual service life of the blade. To resist sand erosion, the coating must withstand prolonged exposure to high-speed particle impacts; therefore, it must possess a certain degree of elasticity. At the same time, the surface of sand is rough and hard, making it easy to scratch coatings; therefore, coatings resistant to sand erosion need not only elasticity but also high mechanical strength. Elasticity and mechanical strength can be quantified by elongation rate and tensile strength, respectively. As long as the coating can maintain these two properties at all times and has sufficient thickness, it can effectively protect against the effects of wind, sand, rain, and fog during the operation of the blades. In environments with rapid temperature fluctuations, the elasticity of coatings generally changes as the temperature varies. Some coatings that exhibit good elasticity at normal temperatures become rigid at low temperatures, which significantly reduces their impact resistance. Therefore, the low-temperature toughness parameters of a coating are an important indicator for determining the performance of elastomeric coatings. High adhesion, high density, high wear resistance, and high weather resistance are the basic requirements for high-performance coatings for wind turbine blades. **"The technical specifications for the surface protection coating on the blades required by the 863” project are as follows: 1. Adhesion ≥ 5 MPa ； 2. Natural air drying/8 hours, drying at 40°C/3 hours ； 3. Wear resistance: 500g/500 revolutions ≤ 20. 4. Salt spray resistance: ≥ 2000 hours, no peeling, adhesion retained at 80% ； 5. The sand and dust resistance test meets the requirements of GB2423.37-89. High-content ceramic coating technology represents a revolutionary approach for enhancing the wear and corrosion resistance of fan blade surfaces. These high-content ceramic coatings contain a large amount of hard, wear-resistant, inert inorganic materials with uniform particle sizes; when applied to metal surfaces, they rapidly form a special protective ceramic coating. This ceramic coating possesses the high hardness and excellent wear resistance of wear-resistant ceramic materials, while also offering better adhesion, superior corrosion resistance, and greater durability compared to conventional organic wear-resistant coatings. The high-content ceramic coating technology has the following advantages: ① It can be applied on-site; it is single-component and low in viscosity, allowing for application using simple methods such as brushing or spraying. ②High adhesion. The coating offers high reliability and a long service life. ③High hardness and good wear resistance. ④Significantly improves corrosion resistance. ⑤Light in weight. The bulk density of the ceramic coating ranges from 1.5 g/c.c to 2.5 g/c.c. It is only 1/4 of that of steel. It can **significantly reduce the load on the equipment, thereby greatly improving its operational efficiency. Unique technologies of wind turbine ceramic coatings: 1. Substrate activation technology: The use of surface activators on the substrate significantly improves the adhesion and sealing properties of the coating. 2. Elastomer technology: The use of elastomers enhances the toughness of coatings, making them more suitable for use in environments subject to motion and vibration, as well as for coating and repairing curved surfaces. The spray-painted polyurethane elastomer technology is another innovative approach for providing wear and corrosion resistance to the surface of fan blades. 1) Wide hardness range. Moreover, it retains good rubber elasticity and elongation even at high hardness. (2) High strength. At rubber hardness, their tensile strength and tear strength are much higher than those of general-purpose rubbers. At plastic hardness, their impact strength and bending strength are much higher than those of plastics. (3) Wear-resistant. It has the reputation of being \"wear-resistant rubber\". Especially under working conditions with moist media such as water present, its wear resistance is often several times that of ordinary rubber materials. Metal materials such as steel are hard, but they are not necessarily wear-resistant. For example, in the Yellow River irrigation areas, the metal rings and protective sleeves of large water pumps are subject to intense erosion by sediment; as a result, they suffer severe wear and start leaking within just a few hundred hours. In contrast, those rings and sleeves covered with polyurethane elastomers remain free from wear even after 1,800 hours of continuous operation. (4) It has good shock absorption, radiation resistance, and breathability. These advantages are precisely the reasons why this type of polyurethane elastomer is widely used in fields such as aerospace, water management, and mining. However, polyurethane elastomers also have their shortcomings. (1) High endogenous heat. The high-temperature resistance is average. In particular, its resistance to heat and moisture is poor. The normal operating temperature should be below 120 degrees. If operating for a long time under high-frequency oscillation conditions, it must be used with an adequate cooling medium. (2) It is not resistant to highly polar solvents and strong acid-base media. At certain temperatures, alcohols, acids, and others can cause polyurethane elastomers to swell and degrade. Dichloromethane, trichloroethylene, and the like can cause polyurethane elastomers to swell at room temperature.