TY - JOUR
T1 - Tribological Properties of Ultrananocrystalline Diamond Films
T2 - Mechanochemical Transformation of Sliding Interfaces
AU - Rani, Revati
AU - Panda, Kalpataru
AU - Kumar, Niranjan
AU - Kozakov, Alexey Titovich
AU - Kolesnikov, Vladimir Ivanovich
AU - Sidashov, Andrey Vyacheslavovich
AU - Lin, I. Nan
N1 - Publisher Copyright:
© 2017 The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Improving the tribological properties of materials in ambient and high vacuum tribo-conditions is useful for inter-atmospheric applications. Highly-hydrogenated and less-hydrogenated ultrananocrystalline diamond (UNCD) films with distinct microstructural characteristics were deposited on Ti-6Al-4 V alloy, by optimizing the plasma conditions in the chemical vapor deposition. Both the UNCD films showed less friction coefficient in ambient atmospheric tribo-contact conditions due to the passivation. This provides chemical stability to UNCD films under the tribo-mechanical stressed conditions which limits the transferlayer formation and conversion of UNCD phase into graphitization/amorphization. However, in the high vacuum tribo-conditions, highly-hydrogenated UNCD films showed low friction value which gradually increased to the higher magnitude at longer sliding cycles. The low friction coefficient was indicative of passivation provided by the hydrogen network intrinsically present in the UNCD films. It gradually desorbs and the dangling bonds are progressively activated in the contact regime, leading to a gradual increase in the friction value. In contrast, less-hydrogenated UNCD films do not exhibit low friction regime in high vacuum conditions due to the lack of internal passivation. In this case, the conversion of UNCD to amorphized carbon structure in the wear tracks and amorphous carbon (a-C) tribofilm formation on ball scars were observed.
AB - Improving the tribological properties of materials in ambient and high vacuum tribo-conditions is useful for inter-atmospheric applications. Highly-hydrogenated and less-hydrogenated ultrananocrystalline diamond (UNCD) films with distinct microstructural characteristics were deposited on Ti-6Al-4 V alloy, by optimizing the plasma conditions in the chemical vapor deposition. Both the UNCD films showed less friction coefficient in ambient atmospheric tribo-contact conditions due to the passivation. This provides chemical stability to UNCD films under the tribo-mechanical stressed conditions which limits the transferlayer formation and conversion of UNCD phase into graphitization/amorphization. However, in the high vacuum tribo-conditions, highly-hydrogenated UNCD films showed low friction value which gradually increased to the higher magnitude at longer sliding cycles. The low friction coefficient was indicative of passivation provided by the hydrogen network intrinsically present in the UNCD films. It gradually desorbs and the dangling bonds are progressively activated in the contact regime, leading to a gradual increase in the friction value. In contrast, less-hydrogenated UNCD films do not exhibit low friction regime in high vacuum conditions due to the lack of internal passivation. In this case, the conversion of UNCD to amorphized carbon structure in the wear tracks and amorphous carbon (a-C) tribofilm formation on ball scars were observed.
UR - https://www.scopus.com/pages/publications/85040452095
UR - https://www.scopus.com/inward/citedby.url?scp=85040452095&partnerID=8YFLogxK
U2 - 10.1038/s41598-017-18425-4
DO - 10.1038/s41598-017-18425-4
M3 - Article
C2 - 29321546
AN - SCOPUS:85040452095
SN - 2045-2322
VL - 8
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 283
ER -