Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 15 No. 6 December 2005|
（1. College of Materials Science and Technology,
Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
2. Institute of Ceramic Materials, Technische Universität Bergakademie Freiberg, Freiberg 09596, Germany）
Abstract: In order to improve the quality of the bio-active coating on medical grade CoNiCrMo substrate, hydroxyapatite(HA) coatings were produced via low-temperature dip-coating route on substrates treated using various surface pre-treating methods. The surface and cross-sectional morphologies of HA coatings were observed by SEM, as well as the bonding strength between coatings and substrates after different pre-treatments were characterized according to ASTM C633. The low-temperature HA dip-coating method with the substrate merely oxidized at 600℃ can provide a high quality HA coating for CoNiCrMo, of which the bonding strength reaches (58±5)MPa, higher than that of the clinically used HA coatings on Ti-alloys produced via plasma spray route, as well as a HA coating with full crystallinity and high phase-purity, which is more in-vivo stable than plasma sprayed HA coating.
Key words: bonding strength; coating; Co-alloys; hydroxyapatite