Al2O3 based composite coatings prepared by plasma spraying

With the development of plasma spraying technology, plasma-sprayed Al2O3-based composite coatings have been widely used in the fields of corrosion protection, wear resistance, aerospace, etc. Firstly, new plasma spraying technologies (la-ser plasma spraying, suspension plasma spraying and supersonic plasma spraying) and main spraying parameters (spraying power, powder feeding method, spraying distance, etc.) were briefly introduced. Then, from the perspective of improving corrosion resistance of the coatings, effects of the second phase, spraying parameters and post-treatment process on porosity of the coatings as well as the relationship between the three factors and corrosion resistance of the coatings were expounded. Then the effects of hardness, feeding characteristics and laser cladding technology on wear resistance of Al2O3-based composite coatings were analyzed emphatically. Factors affecting the hardness, as well as effects of characteristics of spraying powder and laser cladding treatment on microstructure of the composite coating were described in detail. In the aspect of study on electromagnetic absorption properties, effects of adjusting absorber content, coating thickness, various electromagnetic wave absorber matching and spraying parameters on wave absorbing properties of plasma-sprayed Al2O3-based composite coatings were discussed. Finally, prospect of preparing Al2O3-based composite coatings exhibiting better performance by adopting plasma spraying tech-nology were proposed. © 2017, Chongqing Wujiu Periodicals Press. All rights reserved.