Massive nitrogen super-saturation into CoCrMo Alloys for improvement of tribological performance

Massive nitrogen super-saturation into CoCrMo Alloys for improvement of tribological performance

AIZAWA Tatsuhiko, FUNAZUKA Tatsuya, SHIRATORI Tomomi, SUZUKI Yohei

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Abstract. The cobalt-chromium-molybdenum (CoCrMo) superalloys have been utilized in the dental, knee, and hip arthroplasty applications because of their unique combination of high strength, high wear and corrosion resistance. A massive nitrogen supersaturation (MNS) process was proposed as a surface treatment to improve these strength, hardness and ductility, further needed for hip replacement and dental prosthesis. CoCrMo disc specimens were prepared for plasma immersion nitriding at 673 K for 21.6 ks by 50 Pa. The nitrogen solute uniformly distributed in the MNS-layer with the average content of 5 mass%. Higher surface hardness than 1550 HV was attained under application of 10 N. The maximum friction coefficient was halved before and after MNS and this low frictional state with μ< 0.45 was preserved although the sliding condition by 0.1 m/s. Keywords
Plasma Nitriding, Cocrmo Alloys, Massive Nitrogen Interstitials, Low Friction and Wear

Published online 4/24/2024, 11 pages
Copyright © 2024 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: AIZAWA Tatsuhiko, FUNAZUKA Tatsuya, SHIRATORI Tomomi, SUZUKI Yohei, Massive nitrogen super-saturation into CoCrMo Alloys for improvement of tribological performance, Materials Research Proceedings, Vol. 41, pp 1248-1258, 2024


The article was published as article 139 of the book Material Forming

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