Effect of Sb-SnO₂ Doping Amount on Anti-scaling Performance ofAl₂O₃-13%TiO₂ Composite Ceramic Coating

With Al₂O₃-13%TiO₂ (AT13) and nano antimony tin oxide (Sb-SnO₂) powders as raw materials, AT13 composite ceramic coatings doped with different mass fractions (0-16%) of Sb-SnO₂ were prepared on surface of 4145H alloy steel substrate by plasma spraying process, and the surface performance, micromorphology, microhardness, bond strength, and anti-scaling properties in formation produced water of the composite ceramic coatings were investigated and compared with those of the chromium-electrodeposited layer and untreated 4145H alloy steel. The results show that the water contact angle of composite ceramic coating was larger than those of chromium-electrodeposited layer and untreated 4145H alloy steel, and the surface energy was lower. With increasing Sb-SnO₂ doping amount, the water contact angle basically increased first and then decreased, and the surface energy decreased first and then increased. The composite ceramic coating had a large number of pores. With increasing Sb-SnO₂ doping amount, the hardness had an overall decreasing trend, but was higher than those of 4145H alloy steel and chromium-electrodeposited layer. With increasing Sb-SnO₂ doping amount, and the fouling mass per unit area decreased first and then increased. The composite ceramic coating doped with 10wt%Sb-SnO₂ had the largest water contact angle, the smallest surface energy, and the minimum fouling mass per unit area; the average bond strength was 25.7 MPa.