|
4892 |
|
Microstructure and properties of FeCrBNb alloy coatings fabricated by
HVOF thermal spraying
|
|
Komsanti Chokethawai / Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Thailand Apiwat Mahawan / Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand Kiattisak Meekhanthong/ Advanced Surface Technologies Co., Ltd., Thailand Man Tuiprae/ Rajamangala University of Technology Lanna, Chiang Mai 50200, Thailand Sittichai Wirojanupatump/ Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand |
|
High velocity oxy-fuel (HVOF) thermal spraying was used to deposit coatings of FeCrBNb amorphous alloys on a mild steel substrate with the thickness of approximately 300 micrometers. The microstructures of the feedstock powders and the coatings before and after heat treatment were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM). The as-sprayed FeCrBNb alloy coatings contained a mixture of amorphous and crystalline phases. After heat treatment of the coatings above the crystallization temperature about 700 degree Celsius the amorphous phase in the coating devitrified into a multiphase structure. In this FeCrBNb alloy coating, formation of a very fine mixed structure of alpha iron and boride by decomposition of the amorphous phase will be observed, bringing about a hardness of 11 GPa. The wear performance of the as-sprayed coatings before and after heat treatment will be evaluated by abrasive wear testing under unlubricated conditions. The relationship between the microstructure and properties will also be discussed in details. |