Microstructure and properties of NiCr/Cr3C2-BaF2 &middot CaF2 coatings prepared with three kinds of thermal sprayed technologies

作者：Huang Chuan Bing; Du Ling Zhong; Zhang Wei Gang^*; Wang Lu; Hou Guang Ku

来源：Journal of Aeronautical Materials, 2009, 29(6): 70-76.

DOI：10.3969/j.issn.1005-5053.2009.6.014

• Bond strength
• Bonding strength
• Detonation spraying
• Elevated temperature
• Friction and wear
• Friction coefficients
• High temperature
• High velocity oxy-fuel spraying
• Lubrication layer
• Microstructure and properties
• Room temperature
• Spray powders
• Thermal spray
• Thermal spray process
• Tribological properties
• Wear rates

Microstructures, composition, porosity, hardness, bonding strength and tribological properties of NiCr/Cr3C2-BaF2&middot CaF2 coatings prepared with plasma spraying (APS), detonation spraying (DS) and high velocity oxy-fuel spraying (HVOF) was systematically investigated. The results show that using coated spray powders, the decarburization of carbide, oxidation and ablation are reduced in thermal spray process. The NiCr/Cr3C2-BaF2 &middotCaF2 coatings deposited by HVOF and detonation spraying have higher density, hardness and bond strength with comparison to plasma spraying. The friction coefficients of three kinds of NiCr/Cr3C2-BaF2 &middotCaF2coatings decrease with the increasing temperatures, and the high temperature friction coefficients are significantly lower than that at room temperature. The friction coefficients of HVOF and detonation spraying coatings are lower than plasma spraying coating, and HVOF and detonation spraying coatings show better wear-resistance. The friction coefficients and wear rates of three coatings as well as the wear rates of coupled Si3N4 balls are reduced due to the formation of NiCr/Cr3C2-BaF2 &middotCaF2lubrication layer at elevated temperatures.

• 出版日期2009