STP1365: The Production and Properties of Wrought High Carbon Co-Cr-Mo Alloys

    Berry, G
    Technical Manager, Firth Rixson Superalloys Ltd, Glossop, Derbyshire

    Bolton, JD
    Reader in Medical Engineering, University of Bradford, West Yorkshire

    Brown, JB
    Metallurgist, Firth Rixson Superalloys Ltd, Glossop,

    McQuaide, S
    International Exchange Student, California Polytechnic State University, College of Engineering, San Luis Obispo, CA

    Pages: 21    Published: Jan 1999


    Abstract

    The medical implant market's requirement for a forged version of the normally cast only, high carbon (approximately 0.2%) variant of the Co-Cr-Mo alloy, which would combine increased wear resistance with the mechanical properties of the low carbon (approximately 0.05%) variant of Co-Cr-Mo, initiated an investigation to establish a viable manufacturing route for the high carbon variant. Initially, a single melted (vacuum induction melted) cast and forged route, and a metal spraying process were examined. Subsequently a vacuum induction melted, electroslag remelted and hot working route was developed using a number of compositional and thermo mechanical processing variants. The mechanical properties obtained on rolled and forged high carbon Co-Cr-Mo bar from 20mm to 50mm diameter were similar to those of the low carbon variant and also met the requirement of ASTM F1537-94 (warm worked). The wear resistance of the high carbon variant, measured using a pin on disc method, indicated some advantage over the low carbon variant at high applied loads.

    Keywords:

    cobalt alloys (for surgical implants), mechanical properties, high carbon cobalt-chromium-molybdenum, implants, medical, forged, wear resistance


    Paper ID: STP14260S

    Committee/Subcommittee: F04.93

    DOI: 10.1520/STP14260S


    CrossRef ASTM International is a member of CrossRef.