TY - JOUR
T1 - Surface hardening of age-hardenable Cu-Ti alloy by plasma carburization
AU - Semboshi, S.
AU - Iwase, Akihiro
AU - Takasugi, T.
N1 - Funding Information:
The authors are grateful to Prof. S. Hanada and Prof. N. Masahashi of the Institute for Materials Research (IMR) of Tohoku University; Prof. Y. Kaneno of Osaka Prefecture University; Dr. N. Ohtsu of Kitami Institute of Technology; Dr. A. Sugarawa and Mr. T. Kimura of DOWA METALTECH Co., Ltd.; and Dr. N. Tsuji of SDC TANAKA Inc. for useful discussions and comments. The authors also thank Mr. E. Aoyagi and M. Ishikuro of IMR for their technical assistance. Financial support provided by the Japan Society for the Promotion of Science (JSPS) through a Grant-in-Aid for Scientific Research (C) (No. 26420663 ) and by the Japan Copper and Brass Association in 2014 is gratefully acknowledged.
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/12/15
Y1 - 2015/12/15
N2 - Plasma carburization was performed on specimens of a commercially used age-hardenable Cu-Ti alloy, in order to improve its surface hardness and wear toughness. Specimens of a Cu-4mol% Ti alloy were carburized in a methane gas glow discharge plasma at temperatures of 1073K and 1123K for 6h. The plasma-carburization treatment resulted in the formation of two layers of crystalline compounds on the surfaces of the Cu-4mol% Ti alloy specimens: (i) a TiC top layer containing 11at.% oxygen and (ii) a Cu3Ti3O sublayer. The thicknesses of the TiC and Cu3Ti3O layers were approximately 100nm and 900nm, respectively, in the case of the specimen plasma-carburized at 1073K. This led to significant improvements in the surface hardness and wear toughness of the specimen. It was interesting to note that the presence of a carbon-friendly alloying element (Ti) at a concentration of only 4mol% resulted in the formation of a hard TiC layer, leading to the surface hardening of the Cu-based alloy. Furthermore, plasma carburization at a higher temperature of 1123K resulted in the formation of thicker layers of hard TiC and Cu3Ti3O, causing a greater degree of surface hardening. Thus, it was demonstrated that plasma carburization is highly suitable for the surface modification of age-hardenable Cu-Ti dilute alloys.
AB - Plasma carburization was performed on specimens of a commercially used age-hardenable Cu-Ti alloy, in order to improve its surface hardness and wear toughness. Specimens of a Cu-4mol% Ti alloy were carburized in a methane gas glow discharge plasma at temperatures of 1073K and 1123K for 6h. The plasma-carburization treatment resulted in the formation of two layers of crystalline compounds on the surfaces of the Cu-4mol% Ti alloy specimens: (i) a TiC top layer containing 11at.% oxygen and (ii) a Cu3Ti3O sublayer. The thicknesses of the TiC and Cu3Ti3O layers were approximately 100nm and 900nm, respectively, in the case of the specimen plasma-carburized at 1073K. This led to significant improvements in the surface hardness and wear toughness of the specimen. It was interesting to note that the presence of a carbon-friendly alloying element (Ti) at a concentration of only 4mol% resulted in the formation of a hard TiC layer, leading to the surface hardening of the Cu-based alloy. Furthermore, plasma carburization at a higher temperature of 1123K resulted in the formation of thicker layers of hard TiC and Cu3Ti3O, causing a greater degree of surface hardening. Thus, it was demonstrated that plasma carburization is highly suitable for the surface modification of age-hardenable Cu-Ti dilute alloys.
KW - Cu-Ti alloy
KW - Hardness
KW - Plasma carburization
KW - Surface hardening
KW - TiC
KW - Wear toughness
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U2 - 10.1016/j.surfcoat.2015.11.003
DO - 10.1016/j.surfcoat.2015.11.003
M3 - Article
AN - SCOPUS:84949452100
VL - 283
SP - 262
EP - 267
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
SN - 0257-8972
ER -