TY - JOUR
T1 - Carbide formation and dissolution in biomedical CO-CR-MO alloys with different carbon contents during solution treatment
AU - Mineta, Shingo
AU - Namba, Shigenobu
AU - Yoneda, Takashi
AU - Ueda, Kyosuke
AU - Narushima, Takayuki
N1 - Funding Information:
The authors thank Professor Hara and Mr. Soma, Tohoku University, for their useful suggestions on electrolytic extraction, and Dr. Kobayashi for his TEM works. The authors thank the Yoneda Advanced Casting Co., Ltd., for supplying the Co-Cr-Mo alloy ingots used in this study. This work was supported, in part, by the Global COE Program ‘‘Materials Integration, Tohoku University,’’ MEXT, Japan.
PY - 2010/8
Y1 - 2010/8
N2 - The microstructures of as-cast and heat-treated biomedical Co-Cr-Mo (ASTM F75) alloys with four different carbon contents were investigated. The as-cast alloys were solution treated at 1473 to 1548 K for 0 to 43.2 ks. The precipitates in the matrix were electrolytically extracted from the as-cast and heat-treated alloys. An M23C6 type carbide and an intermetallic r phase (Co(Cr,Mo)) were detected as precipitates in the as-cast Co-28Cr-6Mo-0.12C alloy; an M23C6 type carbide, a r phase, an g phase (M6C-M12C type carbide), and a p phase (M2T3X type carbide with a b-manganese structure) were detected in the as-cast Co-28Cr-6Mo-0.15C alloy; and anM23C6 type carbide and an g phase were detected in the as-cast Co-28Cr-6Mo-0.25C and Co-28Cr-6Mo-0.35C alloys. After solution treatment, complete precipitate dissolution occurred in all four alloys. Under incomplete precipitate dissolution conditions, the phase and shape of precipitates depended on the heat-treatment conditions and the carbon content in the alloys. The p phase was detected in the alloys with carbon contents of 0.15, 0.25, and 0.35 mass pct after heat treatment at high temperature such as 1548 K for a short holding time of less than 1.8 ks. The presence of the p phase in the Co-Cr-Mo alloys has been revealed in this study for the first time.
AB - The microstructures of as-cast and heat-treated biomedical Co-Cr-Mo (ASTM F75) alloys with four different carbon contents were investigated. The as-cast alloys were solution treated at 1473 to 1548 K for 0 to 43.2 ks. The precipitates in the matrix were electrolytically extracted from the as-cast and heat-treated alloys. An M23C6 type carbide and an intermetallic r phase (Co(Cr,Mo)) were detected as precipitates in the as-cast Co-28Cr-6Mo-0.12C alloy; an M23C6 type carbide, a r phase, an g phase (M6C-M12C type carbide), and a p phase (M2T3X type carbide with a b-manganese structure) were detected in the as-cast Co-28Cr-6Mo-0.15C alloy; and anM23C6 type carbide and an g phase were detected in the as-cast Co-28Cr-6Mo-0.25C and Co-28Cr-6Mo-0.35C alloys. After solution treatment, complete precipitate dissolution occurred in all four alloys. Under incomplete precipitate dissolution conditions, the phase and shape of precipitates depended on the heat-treatment conditions and the carbon content in the alloys. The p phase was detected in the alloys with carbon contents of 0.15, 0.25, and 0.35 mass pct after heat treatment at high temperature such as 1548 K for a short holding time of less than 1.8 ks. The presence of the p phase in the Co-Cr-Mo alloys has been revealed in this study for the first time.
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U2 - 10.1007/s11661-010-0227-1
DO - 10.1007/s11661-010-0227-1
M3 - Article
AN - SCOPUS:79958836712
SN - 1073-5623
VL - 41
SP - 2129
EP - 2138
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
IS - 8
ER -