Preparation And Study Of Corrosion Resistant And Anti-adhesion Ceramic Coating Under Water-lubrication

Water lubrication, with sea water or fresh water as its working medium, is outstanding as its non-combustible, non-polluting feature, etc, which has been widely used in some developed countries in the fields of food factory, medical equipments or in special situations like ocean exploitation, under water operating system, etc. Besides enough mechanical strength, materials must have high resistance to corrosion and wear, low frictional coefficient and anti-adhesion of the microorganism, because of the specific physical and chemical characteristics of water, which has high corrosion and low lubricating ability in contrast with mineral oil as working medium. In this experiment, we try to improve the wear resistance and corrosion resistance of the components by spraying composite ceramic coating on the metal substrate, as well as improve its anti-adhesion of the microorganism properties by adding anti-adhesion composition.In this experiment, we make P7418 powder with Cr2O3, TiO2 and CuO as its the main composition, we make it into spherical powder by spray drying, then bake it to obtain the powder with good liquidity,which is prepared to be compared with the commercially available P7412 powder. If you examine the samples of P7418 which is made by spray-dried powder morphology, you will find that the powder is spherical, and is better in liquidity than P7412, it can meet the requirements of plasma spraying. The XRD analysis of the two powders shows that the compositions of the powders have little changes for the spray drying technology of the powder is only a simple mixture of the powder by agglomerants.By plasma spraying, we got the P7412 and P7418 coatings with uniform color on the stainless steel substrate. And then, we made composite structure design of these two kinds of coatings, and prepared the P7418 composite coating. These three kinds of experiments on corrosion coating come to the conclusion that P7418 coating porosity is slightly lower than that of the P7412, with the two components in the coating uniformity. As the release of CuO in the corrosive media will increase the porosity in the ceramic coating, the corrosion resistance of the unsealing P7418 coating in 10%HCl,10%NaOH and 10%NaCl is worse than that of P7412. However, the addition of CuO can serve to prevent the anti-adhesion of the microorganism properties. Adding a sealing treatment can not only decrease the porosity of ceramic coatings, but also greatly improve the corrosion resistance of ceramic coatings. When a good anti-adhesion performance of attachment of P7418 composite coating is kept, composite coating have similar corrosion resistance.The electrochemical analysis of P7418 composite coating and P7412 coating shows that P7418 composite coating has higher corrosion tendency than P7412 coating, but similar corrosion current. This also proves that the composite structure design of the coating has already achieved the goal.