Cermet composite coating with a ductile Ni3Al binder phase and an in-situ Cr7C3 augmented phase

• Published in: Intermetallics 2021-11, Vol.138, p.107300, Article 107300
• Main Authors: Jianpeng, Yuan, Yueguang, Yu, Jie, Shen
• Format: Article
• Language: English
• Subjects: Aluminides; Atomizing; Ceramic powders; Ceramics; Cermets; Coatings; Gas atomization; High temperature; Including engines; Inert gas atomization; Mechanical properties; Microstructure; Morphology; Nickel aluminides; Protective coatings; Rare gases; Shock resistance; Thermal shock; Tribological properties; Wear resistance; Wear–resistant
• ISSN: 0966-9795; 1879-0216
• DOI: 10.1016/j.intermet.2021.107300

Boron doped Ni3Al intermetallic and in-situ Cr7C3 composite metal-ceramic powder were prepared by inert gas atomization method, and then the coating was prepared by HVOF. The Ni3Al alloys wet the in-situ ceramic particles well and form a continuous internal acicular crystalline phase. Mechanical property and wear performance testing showed the hardness, thermal shock performance and wear resistance of the coating are retained to temperatures of at least 700 °C. All mechanical properties in the range of 450–700 °C were found to be equal to or higher than comparable NiCr-based NiCr–Cr3C2 coating systems. Initial mechanism study shows that the small size and needle-like morphology of the ceramic particles are the important reasons for the good high temperature properties of the coating. •A new type of metal-cermet powder was formed in situ by vacuum atomization process. (Ni, Cr)3Al was used as the bonding phase, and the fine acicular ceramic phase was dispersed in the bonding phase, which significantly improved the high temperature wear resistance of the material.•The powder is suitable for HVOF spraying, and the prepared coating inherits the material structure and performance characteristics of the powder.•The coating has a good effect of protecting friction pairs. Under the same friction and wear test conditions at 700℃, the wear loss of the worn parts is only one sixth of that of NiCr-Cr3C2. The carbide formed is regular in shape and will not damage the friction pair.