Influence Of Nano Y₂O₃、 CeO₂、 Si₃N₄ On The Structure And Properties Of Corrosion Resistance Ceramic Coating

With the rapid development of modern industrial technology, every industrial sector, especially metallurgy, chemical industry, glass and energy industry, faces increasingly harsh corrosion environment. Under certain particular conditions, common metallic materials, even especial alloy material, can not satisfy the causticity requirement, which leads to serious economic loss. So, how to manufacture excellent spraying materials to prolong the lifespan of the spare parts and reduce the economic losses will be a very important research issue. In the process of producing the spraying material, the work-piece barely gets distorted. It is also easy to operate and high in productivity. As a result, the spare parts can resist corrosion, abrasion, and heat. These qualities can reduce the wearing-down of the equipment, prolong the lifespan of the pipeline, and increase the profit.At present, the national economy and the national defense construction have given rise to serious environmental problems. Under this background, the nano- rare earth oxide such as CeO₂, Y₂O₃, nano-Si3N4, ZrO2 power was added to the Y₂O₃-ZrO₂ spraying in this paper. And the mixture ratio of the nano-powder nanophase materials in the coating was optimized with the orthogonal experimental design. The foundational layer materials, made of NiCr powder, and Subsonic Speed Flame Spraying were used to manufacture the corrosion-resistant ceramic coat whose base material was Q235 steel. The coat structure was analyzed with the light microscope, the scanning electron microscope, energy spectrum analysis and XRD; the wear-resistance, adhesion strength and corrosion resistance of the ceramic coatings have been tested; the mechanism of action of the nano-rare earth oxides and nano-powder in the spray powders and the influence of the new phase on the corrosive property of the alkaline-resistant liquid in the coating have been studied. The results show that: adding the right amount of nano-rare earth oxide CeO₂, Y₂O₃, nano-Si3N4 and ZrO₂ can improve the distribution, structure, compactness, wear resistance, adhesion strength and alkali corrosion resistance of the coat structure.After testing the wear resistance, adhesion strength, alkali corrosion resistance and microstructure of the coat and considering its performance and cost, we got the best mixture ratio: 7%Si3N4+3%CeO2+4%Y₂O₃+45% （micro : nano: 11.25% : 33.75%） ZrO₂+10%MgO+4%CaO+17%NiCr+3%SiO₂+4.7%Al+2.3%Fe₂O₃. In this paper, the new way of making the alkali corrosion-resistant coating with the thermal spray and the basic experimental data have been proposed; the new research direction of the application of the nano-rare earth oxides in the alkali-corrosion coating has been initiated; the new issue of the applying the nano-ceramic coating in the industrial field has been proposed.