D. ChunMing, K. Zhou, S. JinBing, Guangzhou Institute of Non-Ferrous Metals, GuangZhou, China; L. Min, Guangzhou Institute of Non-Ferrous Metals, Guangzhou, China
High-Velocity-Air-Flame (HVAF) sprayed WC-17Co and WC-10Co4Cr coatings exhibited great potential in the replacement of electrolytic hard coating (EHC), and comprehensive properties of such coatings should be not worse than those of electrolytic hard coating. The impingement-resistance of HVAF coatings sprayed on 300M high strength steel was studied in this paper. As an important property index, the fracture toughness of the coatings was measured using micro-indentation method at the load of 1, 3 and 5Kgf respectively. The cracks resulted from stress concentration in the micro-indentation were analyzed. The impingement-resistance for both two HVAF WC coatings and EHC coating were evaluated according to the ASTM D3170 standard, and the dropping steel-ball experimentation were performed at the height of 24, 60, 72, 93 and 102 inches respectively. The cracks resulted from both impingements were analyzed using SEM and optical micrograph in comparison with cracks in indentation test. Keywords: HVAF WC coatings, impingement-resistance, fracture toughness..
Summary: this work evaluated the impingement-resistance of HVAF WC coating in comparison with Electrolytic hard coating.
