Fabrication of conventional and nanostructured NiCrC coatings via HVAF technique

• Published in: Transactions of Nonferrous Metals Society of China Vol. 18; no. 2; pp. 262 - 269
• Main Author: 陶凯 张杰 崔华 周香林 张济山
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2008; State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China%School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
• Subjects: coating; HVAF spraying; nanostructure; NiCrC; properties; 喷雾技术; 纳米材料; nanostructure; NiCrC; coating; HVAF spraying; properties
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(08)60046-1

The conventional and nanostructured NiCrC （with chemical composition of 80%NiCr-20%CrC） coatings with high quality were fabricated via high velocity air-fuel（HVAF） spraying technique. The microstructures of these coatings were characterized by means of metallographic microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffractometry. A Vickers microhardness tester was used to determine the mechanical properties of the as-sprayed coatings. The single-line approximation（SLA） method was employed to calculate the grain size and microstrain of as-sprayed nanostructured coating based on the XRD data. The results show that nanostructured NiCrC coating possesses a more uniform and denser microstructure, much higher microhardness and better fracture toughness than its conventional counterpart. Both TEM observation and calculation results based on XRD profile show that as-sprayed nanostructured NiCrC coating has a homogeneous nanocrystalline microstructure with an average grain size of 40 nm.