TY - JOUR
T1 - Hard coating of ultrananocrystalline diamond/nonhydrogenated amorphous carbon composite films on cemented tungsten carbide by coaxial arc plasma deposition
AU - Naragino, Hiroshi
AU - Egiza, Mohamed
AU - Tominaga, Aki
AU - Murasawa, Koki
AU - Gonda, Hidenobu
AU - Sakurai, Masatoshi
AU - Yoshitake, Tsuyoshi
N1 - Funding Information:
This research was partially supported by Osawa Scientific Studies Grants Foundation, JSPS KAKENHI Grant-in-Aid for JSPS Fellows (Grant No. 15J00654), Grant-in-Aid for Young Scientists (B) (Grant No. 26790019), and JST A-STEP (Grant No. AS2511118 M). The experiment using synchrotron radiation was performed at SAGA-LS with the approval of the Kyushu Synchrotron Light Research Center (Proposal Nos. 1505044S/BL15 and 1410105S/BL12).
Publisher Copyright:
© 2016, Springer-Verlag Berlin Heidelberg.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Ultrananocrystalline diamond (UNCD)/nonhydrogenated amorphous carbon (a-C) composite (UNCD/a-C) films were deposited on cemented carbide containing Co by coaxial arc plasma deposition. With decreasing substrate temperature, the hardness was enhanced accompanied by an enhancement in the sp3/(sp2 + sp3). Energy-dispersive X-ray and secondary ion mass spectrometry spectroscopic measurements exhibited that the diffusion of Co atoms from the substrates into the films hardly occurs. The film deposited at room temperature exhibited the maximum hardness of 51.3 GPa and Young’s modulus of 520.2 GPa, which evidently indicates that graphitization induced by Co in the WC substrates, and thermal deformation from sp3 to sp2 bonding are suppressed. The hard UNCD/a-C films can be deposited at a thickness of approximately 3 μm, which is an order larger than that of comparably hard a-C films. The internal compressive stress of the 51.3-GPa film is 4.5 GPa, which is evidently smaller than that of comparably hard a-C films. This is a reason for the thick deposition. The presence of a large number of grain boundaries in the film, which is a structural specific to UNCD/a-C films, might play a role in releasing the internal stress of the films.
AB - Ultrananocrystalline diamond (UNCD)/nonhydrogenated amorphous carbon (a-C) composite (UNCD/a-C) films were deposited on cemented carbide containing Co by coaxial arc plasma deposition. With decreasing substrate temperature, the hardness was enhanced accompanied by an enhancement in the sp3/(sp2 + sp3). Energy-dispersive X-ray and secondary ion mass spectrometry spectroscopic measurements exhibited that the diffusion of Co atoms from the substrates into the films hardly occurs. The film deposited at room temperature exhibited the maximum hardness of 51.3 GPa and Young’s modulus of 520.2 GPa, which evidently indicates that graphitization induced by Co in the WC substrates, and thermal deformation from sp3 to sp2 bonding are suppressed. The hard UNCD/a-C films can be deposited at a thickness of approximately 3 μm, which is an order larger than that of comparably hard a-C films. The internal compressive stress of the 51.3-GPa film is 4.5 GPa, which is evidently smaller than that of comparably hard a-C films. This is a reason for the thick deposition. The presence of a large number of grain boundaries in the film, which is a structural specific to UNCD/a-C films, might play a role in releasing the internal stress of the films.
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U2 - 10.1007/s00339-016-0284-4
DO - 10.1007/s00339-016-0284-4
M3 - Article
AN - SCOPUS:84979517838
SN - 0947-8396
VL - 122
JO - Applied Physics A: Materials Science and Processing
JF - Applied Physics A: Materials Science and Processing
IS - 8
M1 - 761
ER -