TY - GEN
T1 - Nitrogen-enhanced nanostructural evolution and its effect on phase stability in biomedical Co-Cr-Mo alloys
AU - Yamanaka, Kenta
AU - Mori, Manami
AU - Chiba, Akihiko
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014
Y1 - 2014
N2 - Nitrogen addition is known to effectively suppress the athermal γ (fcc) → ε (hcp) martensitic transformation of biomedical Co-Cr-Mo alloys and ultimately provides a combination of high strength and good ductility. In this work, the nanostructural evolution and its influence on dislocation slip as an elementary process in the martensitic transformation were investigated to reveal the origin of their enhanced γ phase stability due to nitrogen addition. The biomedical Co-29Cr-6Mo (wt.%) alloys containing nitrogen in different concentrations (0-0.24 wt.%) were prepared. A single phase γ matrix was attained by adding nitrogen contents higher than 0.1 wt.%. We discovered nanosized Cr2N precipitates that form on the {111}γ planes in the N-containing alloy specimens. It was revealed that the nanoscale inhomogeneities function as obstacles to the glide of partial dislocations and consequently significantly retard the γ → ε martensitic transformation. Since the formation of ε martensite plays a crucial role in plastic deformation and wear behavior, the developed nanostructural modification associated with nitrogen addition must be a promising strategy for highly durable orthopedic implants. Technology (MEXT), Japan.
AB - Nitrogen addition is known to effectively suppress the athermal γ (fcc) → ε (hcp) martensitic transformation of biomedical Co-Cr-Mo alloys and ultimately provides a combination of high strength and good ductility. In this work, the nanostructural evolution and its influence on dislocation slip as an elementary process in the martensitic transformation were investigated to reveal the origin of their enhanced γ phase stability due to nitrogen addition. The biomedical Co-29Cr-6Mo (wt.%) alloys containing nitrogen in different concentrations (0-0.24 wt.%) were prepared. A single phase γ matrix was attained by adding nitrogen contents higher than 0.1 wt.%. We discovered nanosized Cr2N precipitates that form on the {111}γ planes in the N-containing alloy specimens. It was revealed that the nanoscale inhomogeneities function as obstacles to the glide of partial dislocations and consequently significantly retard the γ → ε martensitic transformation. Since the formation of ε martensite plays a crucial role in plastic deformation and wear behavior, the developed nanostructural modification associated with nitrogen addition must be a promising strategy for highly durable orthopedic implants. Technology (MEXT), Japan.
KW - Biomedical Co-Cr-Mo alloys
KW - Dislocations
KW - Nanoprecipitates
KW - Nitrogen addition
KW - Phase stability
UR - http://www.scopus.com/inward/record.url?scp=84901506775&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84901506775&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/AMR.922.826
DO - 10.4028/www.scientific.net/AMR.922.826
M3 - Conference contribution
AN - SCOPUS:84901506775
SN - 9783038350743
T3 - Advanced Materials Research
SP - 826
EP - 831
BT - THERMEC 2013 Supplement
PB - Trans Tech Publications
T2 - 8th International Conference on Processing and Manufacturing of Advanced Materials: Processing, Fabrication, Properties, Applications, THERMEC 2013
Y2 - 2 December 2013 through 6 December 2013
ER -