Erosion Behavior of Plasma-sprayed and Laser-remelted Ceramic Coatings on TiAl Intermetallic Surface
TiAl intermetallics are new types of high-temperature structural materials applied for aerospace and aircraft industry because of their low density, high strength and good creep-resistance. Ceramic coating technique on metal surface is a promising means to combine advantages of the metal substrate and the ceramic coating, which can simultaneously meet mechanical properties and environmental service demands. In the present study, Al2O3-13wt.%TiO2 ceramic coatings prepared by plasma spraying on TiAl intermetallic surface were remelted by laser. The microstructure and microhardness of the coatings were investigated using scanning electron microscopy (SEM) and microhardness measurement. Meanwhile, the erosion wear behavior of the as-sprayed and laser-remelted coatings were analyzed and compared. The results show that the plasma-sprayed coating has a typical lamella-like structure and has some pores. The laserremelted coating exhibits obvious layer-like characteristic. According to the microstructural difference, the ceramic coating can be divided into the remelted zone, the sintered zone and remained plasma-sprayed zone. Owing to the compact microstructure and refined grains, the laser-remelted coating has higher microhardness and better erosion resistance than the as-sprayed coating. The erosion rate increased as the impingement angle increased for both as-sprayed and laser-remelted coatings. And the ceramic coatings showed a typical brittleness erosion mechanism. Owing to the limited bonding at the interfaces between lamella, the spalling of ceramic particles from the lamellar interface may be mainly responsible for the erosion of the plasma-sprayed coating. In contrast, cracking occurs within region near the surface of the laser-remelted ceramic coating and that erosion occurs by removal of these small blocks.
Laser remelting Plasma spraying Ceramic coating Erosion resistance TiAl intermetallic
Zongjun Tian Dongsheng Wang Lida Shen Zhidong Liu Yinhui Huang
College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics
国际会议
The 16th International Symposium on Electromachining(第16届国际电加工会议)
上海
英文
437-442
2010-04-19（万方平台首次上网日期，不代表论文的发表时间）