WC-Co 초고속 화염용사코팅 표면특성에 미치는 분말입자의 크기 |
조동율1,3, 윤재홍1, 윤상환1, 주윤곤1, 최원호2, 손영복2 |
1창원국립대학교 신소재공학부 2㈜지닉스용사 3한국과학기술정보연구원 |
The Effects of Particle Size on the Surface Properties of an HVOF Coating of WC-Co |
Tong Yul Cho1,3, Jae Hong Yoon1, Sang Hwan Yoon1, Yun Kon Joo1, Won Ho Choi2, Young Bok Son2 |
1School of Materials Science and Engineering, Changwon National University, Changwon 51140, Republic of Korea 2Xinix Metallizing Co., Ltd, Gyungnam 52006, Republic of Korea 3Korea Institute of Science and Technology Information, Seoul 02456, Republic of Korea |
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Received: 22 August 2016; Accepted: 28 October 2016. Published online: 6 April 2017. |
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ABSTRACT |
The effects of particle size on the surface properties of HVOF spray coating were studied to improve of the durability of metal components. Micro and nano sized WC-12Co powders were coated on the surface of Inconel718, and the effects of particle size on surface properties were studied. Surface hardness was reduced when the particle sizes of the powder were decreased, because the larger specific surface area of the smaller particles caused greater heat absorption and decomposition of the hard WC to less hard W2C and graphite. Porosity was increased by decreasing the particle size, because the larger specific surface area of the smaller particles caused a greater decomposition of WC to W2C and free carbon. The free carbon formed carbon oxide gases which created the porous surface. The friction coefficient was reduced by decreasing the particle size because the larger specific surface area of the smaller particles produced more free carbon free Co and Co oxide which acted as solid lubricants. The friction coefficient increased when the surface temperature was increased from 25 to 500 ℃, due to local cold welding. To improve the durability of metal mechanical components, WC-Co coating with the proper particle size is recommended. |
Keywords:
surface properties, powder, HVOF coating |
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