TY - JOUR
T1 - Characterization of surface layer formed by gas blow induction heating nitriding at different temperatures and its effect on the fatigue properties of titanium alloy
AU - Takesue, Shogo
AU - Kikuchi, Shoichi
AU - Akebono, Hiroyuki
AU - Morita, Tatsuro
AU - Komotori, Jun
N1 - Funding Information:
Part of this study was supported by The Light Metal Educational Foundation, Inc. . The authors are grateful for their financial support. We also thank Neturen Co., Ltd. For their support of induction heating equipment and Dr. Kazutoshi Katahira (Materials Fabrication Laboratory, RIKEN) for help with the observations of the wear tracks.
Funding Information:
Part of this study was supported by The Light Metal Educational Foundation, Inc. The authors are grateful for their financial support. We also thank Neturen Co. Ltd. For their support of induction heating equipment and Dr. Kazutoshi Katahira (Materials Fabrication Laboratory, RIKEN) for help with the observations of the wear tracks.
Publisher Copyright:
© 2020 The Authors
PY - 2020/3
Y1 - 2020/3
N2 - Gas blow induction heating (GBIH) nitriding was carried out for Ti–6Al–4V alloy at different temperatures, and its effect on surface characteristics, wear resistance and fatigue properties was investigated. The microstructures of the specimen surface were characterized using optical microscopy, laser microscopy, X-ray diffraction, micro-Vickers hardness tester, and nano-indentation tester. It was found that the surface characteristics of titanium alloy varied with increasing the treatment temperature of GBIH-nitriding. In this study, a nitrogen diffusion layer was formed on the titanium alloy surface GBIH-nitrided at 1073 K. A nitrogen compound layer and diffusion layer were created at the treatment temperature of 1173 K, which suppressed the wear loss to under one tenth that of the substrate. In order to examine the fatigue properties of the treated alloy, fatigue tests under four-point bending were performed. The fatigue strength of the Ti–6Al–4V alloy GBIH-nitrided at 1173 K was 234 MPa lower than that of the mirror-polished alloy. The decrease in the fatigue strength is due to the formation of the compound layer with a Young's modulus approximately twice that of the substrate, and the grain coarsening from 7 μm to 300 μm. The results indicate that a thick nitrided layer with high hardness and the close Young's modulus to the substrate improved the fatigue strength of the Ti–6Al–4V alloy.
AB - Gas blow induction heating (GBIH) nitriding was carried out for Ti–6Al–4V alloy at different temperatures, and its effect on surface characteristics, wear resistance and fatigue properties was investigated. The microstructures of the specimen surface were characterized using optical microscopy, laser microscopy, X-ray diffraction, micro-Vickers hardness tester, and nano-indentation tester. It was found that the surface characteristics of titanium alloy varied with increasing the treatment temperature of GBIH-nitriding. In this study, a nitrogen diffusion layer was formed on the titanium alloy surface GBIH-nitrided at 1073 K. A nitrogen compound layer and diffusion layer were created at the treatment temperature of 1173 K, which suppressed the wear loss to under one tenth that of the substrate. In order to examine the fatigue properties of the treated alloy, fatigue tests under four-point bending were performed. The fatigue strength of the Ti–6Al–4V alloy GBIH-nitrided at 1173 K was 234 MPa lower than that of the mirror-polished alloy. The decrease in the fatigue strength is due to the formation of the compound layer with a Young's modulus approximately twice that of the substrate, and the grain coarsening from 7 μm to 300 μm. The results indicate that a thick nitrided layer with high hardness and the close Young's modulus to the substrate improved the fatigue strength of the Ti–6Al–4V alloy.
KW - Fatigue
KW - Induction heating
KW - Microstructure
KW - Nitriding
KW - Titanium alloy
UR - http://www.scopus.com/inward/record.url?scp=85086370353&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85086370353&partnerID=8YFLogxK
U2 - 10.1016/j.rinma.2020.100071
DO - 10.1016/j.rinma.2020.100071
M3 - Article
AN - SCOPUS:85086370353
VL - 5
JO - Results in Materials
JF - Results in Materials
SN - 2590-048X
M1 - 100071
ER -