Microstructure and properties of Al₂O₃-13%TiO₂ coatings sprayed using nanostructured powders

ZHANG Jianxin, HE Jining, DONG Yanchun, LI Xiangzhi, and YAN Dianran School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China

摘 要：The microstructure and wear performance of Al2O3-13% TiO2 coatings prepared by plasma spraying of agglom- erated nanoparticle powders were investigated. SEM analysis showed that the as-sprayed Al2O3-TiO2 coatings comprise of two kinds of typical region: fully melted region and unmelted/partially melted nanostructured region, which is different than the conventional coating with lamellar structure. It is shown that the microhardness of the nanostructured coatings was about 15%-30% higher than that of the conventional coating and the wear resistance is significantly improved, especially under a high wear load. The nanostructured coating sprayed at a lower power shows a lower wear resistance than the coat- ings produced at a higher power, because of the presence of pores and microstructural defects which are detrimental to the fracture toughness of the coatings.

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