TY - GEN
T1 - Effect of nitrogen addition on isothermal phase transformation and mechanical properties in biomedical Co-Cr-Mo alloys
AU - Kurosu, Shingo
AU - Matsumoto, Hiroaki
AU - Chiba, Akihiko
PY - 2010/5/21
Y1 - 2010/5/21
N2 - Effect of nitrogen addition on isothermal phase transformation behavior in a biomedical Co-Cr-Mo alloy without addition of carbon was investigated during aging at temperature between 973 K and 1273 K for up to 90 ks. In the Co-Cr-Mo alloy, phase transformation from fcc to hcp1 with super-saturation of Cr occurred by massive transformation. With prolonged aging treatment, a lamellar structure consisting of hcp2 with equilibrium of Cr and σ phases was formed at hcp1/hcp1 boundaries by a discontinuous/cellular reaction, expressed by the reaction equation hcp 1→hcp2+σ. The phase transformation is remarkably changed by addition of nitrogen. In the Co-Cr-Mo-N alloy, the phase transformation from fcc to hcp occurs with a significant long incubation period compared with that in Co-Cr-Mo alloy. Besides, lamellar M2N(M=Cr, Mo, Co) precipitates during phase transformation, suggesting that phase transformation of Co-Cr-Mo-N alloy may be dominant by the eutectoid transformation (fcc→hcp+M2N).
AB - Effect of nitrogen addition on isothermal phase transformation behavior in a biomedical Co-Cr-Mo alloy without addition of carbon was investigated during aging at temperature between 973 K and 1273 K for up to 90 ks. In the Co-Cr-Mo alloy, phase transformation from fcc to hcp1 with super-saturation of Cr occurred by massive transformation. With prolonged aging treatment, a lamellar structure consisting of hcp2 with equilibrium of Cr and σ phases was formed at hcp1/hcp1 boundaries by a discontinuous/cellular reaction, expressed by the reaction equation hcp 1→hcp2+σ. The phase transformation is remarkably changed by addition of nitrogen. In the Co-Cr-Mo-N alloy, the phase transformation from fcc to hcp occurs with a significant long incubation period compared with that in Co-Cr-Mo alloy. Besides, lamellar M2N(M=Cr, Mo, Co) precipitates during phase transformation, suggesting that phase transformation of Co-Cr-Mo-N alloy may be dominant by the eutectoid transformation (fcc→hcp+M2N).
KW - Biomaterial
KW - Cobalt-chromium-molybdenum alloy
KW - Mechanical properties
KW - Phase transformation
UR - http://www.scopus.com/inward/record.url?scp=77952405757&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77952405757&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:77952405757
SN - 9780873397537
T3 - TMS Annual Meeting
SP - 707
EP - 714
BT - TMS 2010 - 139th Annual Meeting and Exhibition - Supplemental Proceedings
T2 - TMS 2010 - 139th Annual Meeting and Exhibition
Y2 - 14 February 2010 through 18 February 2010
ER -