UCL  IRIS
Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data shown on the profile page to:

http://www.ucl.ac.uk/finance/secure/research/post_award
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Mechanism of Chromium Oxide Formation in Cobalt-Chromium-Molybdenum (F75) Alloys Prepared Using Spark Plasma Sintering
  • Publication Type:
    Journal article
  • Publication Sub Type:
    Article
  • Authors:
    Patel B, Inam F, Reece MJ, Edirisinghe M, Bonfield W, Huang J, Angadji A
  • Publisher:
    WILEY-BLACKWELL
  • Publication date:
    05/2011
  • Pagination:
    411, 417
  • Journal:
    ADV ENG MATER
  • Volume:
    13
  • Issue:
    5
  • Print ISSN:
    1438-1656
  • Language:
    EN
  • Keywords:
    CO-CR-MO, METAL-ON-METAL, IMPLANT ALLOYS, ION RELEASE, BASE ALLOYS, WEAR, CAST, RESISTANCE, SYSTEM, TRANSFORMATION
  • Addresses:
    Patel, B
    UCL
    Dept Mech Engn
    London
    WC1E 7JE
    England

    Queen Mary Univ London
    Nanoforce Technol Ltd
    London
    E1 4NS
    England
Abstract
Metallic implants are known to have higher wear rates compared to ceramic. This causes more wear debris to be produced and results in the release of toxic metal ions to the surrounding areas. The strengthening mechanism in cobalt based cast orthopedic alloys depends upon carbides present in the microstructure, but these cause problems when dislodged between articulating surfaces, accelerating wear by abrasion and fretting. Thus, in order to improve the performance of these implants a novel method of processing the alloys, namely by spark plasma sintering (SPS) of fine powders, has been used as it generates hard oxides and not carbides in the microstructure. The oxide in the SPS processed alloy is identified as chromium oxide formed by a redox reaction between cobalt oxide found on the surface of cobalt particles and chromium. The oxygen associated with the cobalt powder is displaced and combines with the chromium during SPS. This oxide in the microstructure of the alloy can be more beneficial than carbides due to its higher hardness, resulting in lower wear rates and less wear particles. With the oxide in the microstructure, the hardness of the alloy becomes closer to that of ceramics. Also its lower density enables the alloy to be lighter. The chemical stability of the oxide ensures that it remains intact and due its insolubility in water, no carcinogenic or toxic reactions will occur.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
UCL Authors
Dept of Mechanical Engineering
Dept of Mechanical Engineering
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by