Study on Corrosion Resistance of Ceramic Spraying

       With the advancement of nanomaterial preparation technology, research on the use of nanomaterials in surface engineering has also attracted more and more attention. It is in this context that



A brand-new discipline of ceramic spraying - nano-surface engineering came into being. The so-called nano-surface engineering is based on nano-materials and nano-processing technology. Through specific processing skills and assembly methods, the surface of the material has a nano-structure, and then the surface of the material can be strengthened, modified or given new functions. Advanced processing technology, It has great academic value, usage prospects and market potential.







Because of its high flame temperature, fast jet velocity, fast cooling rate, and controllable atmosphere, ceramic spraying technology is one of the most important methods for preparing nano-coatings. Plasma sprayed Al2O3-TiO2 ceramic composite ceramic coating has the advantages of high hardness, high temperature resistance, wear resistance and corrosion resistance, which has a good maintenance effect on the metal matrix, and can effectively prolong the service life of the components, so it is obtained in many industries. to use.







Early researches on Al2O3-TiO2 ceramic composite coatings mainly focused on the analysis of its microstructure and phase composition, while less research on the coating's preparation process and its properties, especially corrosion resistance. Therefore, this paper discusses the influence rules of spraying power and TiO2 content on the corrosion resistance of Al2O3-TiO2 nano-ceramic composite coatings prepared by plasma spraying.



Taking 6063 aluminum alloy as the matrix material, its chemical composition is (mass fraction, %): 0.2～0.6Si, 0.35Fe, 0.1Cu, 0.1Mn, 0.45～0.9Mg, 0.1Cr, 0.1Zn, 0.1Ti, and the balance Al . The dimensions of the sprayed samples are 60 mm × 40 mm × 3 mm. The nano-powder is sprayed and re-granulated to prepare micron-scale feed suitable for spraying. The process flow is: manufacturing slurry: 97%Al2O3+3%TiO2 (mass percentage, referred to as AT3, the same below); 87%Al2O3+13% TiO2 (AT13 for short); 80%Al2O3+20%TiO2 (AT20 for short); 60%Al2O3+40%TiO2 (AT40 for short)→spray granulation→powder sintering (800℃×1h)→selection. Degrease and sandblast the surface of the substrate before spraying. The internal powder feeding method is used for spraying, the spraying power is 20, 25, 30 and 35kW respectively, the argon gas flow is 120L/min, the powder feeding nitrogen pressure is 0.6MPa, and the spraying interval is 70mm.







Spray thickness 0.15 ~ 0.20mm. The corrosion resistance of the coating was characterized by a neutral salt spray test. The experimental period is determined as 4, 8, 24, 48, 72, 96 and 120h according to the period recommended in the specification and combined with the actual situation. The spraying is not stopped during the experimental period, and the salt spray box is opened only when the required time is short to investigate the sample.







The spraying power has a significant effect on the corrosion resistance of the nano-ceramic composite coating. With the increase of spraying power, the corrosion resistance of nano-ceramic composite coating first increased and then decreased. The content of TiO2 has a great influence on the corrosion resistance of nano-ceramic composite coatings, and its corrosion resistance increases with the increase of TiO2 content.