TY - JOUR
T1 - The effect of temperature on lubrication property with modtc-containning lubricant -Temperature dependence of friction coefficient and tribofilm structure
AU - Komaba, Masanori
AU - Kondo, Shinya
AU - Suzuki, Atsushi
AU - Kurihara, Kazue
AU - Mori, Shigeyuki
PY - 2017
Y1 - 2017
N2 - The effect of temperature on the lubrication performance of molybdenum dithiocarbamate (MoDTC) was investigated by a ball on disk tribometer with lubricant oil containing MoDTC and calcium sulfonate (CaSU) at temperatures of 25∗C, 40∗C, 60∗C and 80°C. The behavior of friction coefficient was closely dependent on the oil temperature. Friction coefficient decreased after a certain induction period and became to be constant at a steady state. At higher temperature, the induction period became to be shorter, and the slope of decreasing friction coefficient became to be steeper. Friction coefficient at a steady state decreased at higher temperature, and was changed reversibly when the oil temperature was changed. Oscillatory change in friction was observed when the oil temperature was changed periodically. Chemical analysis of the tribofilm with X-ray Photoelectron Spectroscopy (XPS) revealed that higher content of Mo (IV) as a component of molybdenum disulfide (M0S2) observed in the tribofilm formed at higher temperature. Highly oriented M0S2 layer was observed with High Resolution Transmission Electron Microscopy (HR-TEM) in the tribofilm formed at 80"C. It was found that the structure of tribofilm is altered reversibly with oil temperature. A steady state model of tribofilm formation was proposed on the basis of observed results.
AB - The effect of temperature on the lubrication performance of molybdenum dithiocarbamate (MoDTC) was investigated by a ball on disk tribometer with lubricant oil containing MoDTC and calcium sulfonate (CaSU) at temperatures of 25∗C, 40∗C, 60∗C and 80°C. The behavior of friction coefficient was closely dependent on the oil temperature. Friction coefficient decreased after a certain induction period and became to be constant at a steady state. At higher temperature, the induction period became to be shorter, and the slope of decreasing friction coefficient became to be steeper. Friction coefficient at a steady state decreased at higher temperature, and was changed reversibly when the oil temperature was changed. Oscillatory change in friction was observed when the oil temperature was changed periodically. Chemical analysis of the tribofilm with X-ray Photoelectron Spectroscopy (XPS) revealed that higher content of Mo (IV) as a component of molybdenum disulfide (M0S2) observed in the tribofilm formed at higher temperature. Highly oriented M0S2 layer was observed with High Resolution Transmission Electron Microscopy (HR-TEM) in the tribofilm formed at 80"C. It was found that the structure of tribofilm is altered reversibly with oil temperature. A steady state model of tribofilm formation was proposed on the basis of observed results.
KW - Friction coefficient
KW - High resolution transmission electron microscopy
KW - Layer structure
KW - Molybdenum disulfide
KW - Molybdenum dithiocarbamate
KW - Temperature dependence
KW - Tribochemistry
KW - Tribofilm. x-ray photoelectron spectroscopy
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M3 - Article
AN - SCOPUS:85037808233
SN - 0915-1168
VL - 62
SP - 703
EP - 710
JO - Toraibarojisuto/Journal of Japanese Society of Tribologists
JF - Toraibarojisuto/Journal of Japanese Society of Tribologists
IS - 11
ER -