中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 18 No. 2 April 2008 |
（1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China;2. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract: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.
Key words: HVAF spraying; nanostructure; coating; NiCrC; properties
