TY - JOUR
T1 - Effect of building position on phase distribution in Co-Cr-Mo alloy additive manufactured by electron-beam melting
AU - Takashima, Taiyo
AU - Koizumi, Yuichiro
AU - Li, Yunping
AU - Yamanaka, Kenta
AU - Saito, Tsuyoshi
AU - Chiba, Akihiko
N1 - Funding Information:
The authors greatly thank Dr. Shi-Hai Sun (formerly graduate student of Tohoku University, currently assistant professor of Osaka University) for his kind support for conducting this study and preparing for the manuscript. This research was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) KAKENHI (Grant Numbers: 26289252, 15K14154). A part of this work was performed under the inter-university cooperative research program (Proposal No. 14G0411) of the Cooperative Research and Development Center for Advanced Materials, Institute for Materials Research, Tohoku University.
Publisher Copyright:
© 2016 The Japan Institute of Metals and Materials.
PY - 2016
Y1 - 2016
N2 - Cobalt-chromium-molybdenum (Co-Cr-Mo) alloys are used for biomedical implants such as artificial joints because they have excellent wear and corrosion resistance and biocompatibility. Electron-beam melting (EBM) is a type of additive manufacturing technique for metals. We used EBM to fabricate 20 rods of a Co-Cr-Mo alloy with height of 160 mm arranged in a 4× 5 matrix and observed the phase constitution in the middle part (at a height of 80 mm) of the rods by scanning electron microscopy-electron backscatter diffraction. We found that the rods in the center part of the matrix consisted of more of the face-centered cubic (γ) phase and less of the hexagonal close-packed (ϵ) phase than rods in the outer part. This happened because even though each rod was fabricated under the same beam condition, the rods at the center had been exposed to higher temperature than those in the outer part, and less thermal dissipation took place because the neighboring rods were also heated by the electron beam. This difference in the thermal histories should be taken into consideration when many objects are fabricated simultaneously.
AB - Cobalt-chromium-molybdenum (Co-Cr-Mo) alloys are used for biomedical implants such as artificial joints because they have excellent wear and corrosion resistance and biocompatibility. Electron-beam melting (EBM) is a type of additive manufacturing technique for metals. We used EBM to fabricate 20 rods of a Co-Cr-Mo alloy with height of 160 mm arranged in a 4× 5 matrix and observed the phase constitution in the middle part (at a height of 80 mm) of the rods by scanning electron microscopy-electron backscatter diffraction. We found that the rods in the center part of the matrix consisted of more of the face-centered cubic (γ) phase and less of the hexagonal close-packed (ϵ) phase than rods in the outer part. This happened because even though each rod was fabricated under the same beam condition, the rods at the center had been exposed to higher temperature than those in the outer part, and less thermal dissipation took place because the neighboring rods were also heated by the electron beam. This difference in the thermal histories should be taken into consideration when many objects are fabricated simultaneously.
KW - Biomedical cobalt-chromium-molybdenum alloy
KW - Custom-made artificial joints
KW - Electron-beam melting
KW - Preheat
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U2 - 10.2320/matertrans.Y-M2016826
DO - 10.2320/matertrans.Y-M2016826
M3 - Article
AN - SCOPUS:84998655053
SN - 1345-9678
VL - 57
SP - 2041
EP - 2047
JO - Materials Transactions
JF - Materials Transactions
IS - 12
ER -