Microstructures and properties of submicron structural WC-12Co coatings deposited by HVOF

作者：Ye Fuxing^*; Cui Chong; Yang Xue; Wang Xibao; Kazuhiro Nakata

来源：China Welding, 2011, 20(4): 22-27.

• Deposition efficiencies
• Dry wear
• Feedstock powders
• Friction coefficients
• High velocity oxy-fuel spraying
• HVOF system
• Linear relationships
• Microstructures and properties
• Porosity of coatings
• Rotational speed
• Spraying parameters
• Submicron
• Submicron grains
• WC-12Co
• WC-Co coating
• Wear ring
• Wear-resistant coating
• Weight loss

In this study, WC-Co powder with WC submicron grain size of 0.7-0.9 μm was used as feedstock powder to deposit wear resistant coating by home-made TJ-9000 HVOF system. The deposition efficiency of the feedstock powder was examined. Influences of the High Velocity Oxy-Fuel (HVOF) spraying parameters on the microstructures, phase compositions, microhardness, and wear resistance of sprayed coatings were investigated. The deposition efficiency of the feedstock powder was very high, and reached to 58%. The sprayed coatings were very dense, and their porosities were lower than 1% and could be lowered than 0.42% with optimal spraying parameters. According to the X-ray Diffraction (XRD) analysis, the phase compositions of the sprayed coatings consisted of WC, Co, W2C, and Co6W6C. W appeared at high flame power. The average microhardness of the coating was 1100 HV0.1 and had reversely linear relationship with the porosity of coatings. The weight loss of the counter wear ring GCr15 was 20 times than that of the sprayed WC-Co coating. At the load of 15 kg and rotational speed of 200 r/min of GCr15 counter wear ring, the friction coefficient was 0.68 in the dry wear conditions. It was concluded that the sprayed submicron structural WC-12Co coating had good wear resistance.

• 出版日期2011
• 单位天津大学