JOURNAL OF JAPANESE SOCIETY OF TRIBOLOGISTS
Online ISSN : 2189-9967
Print ISSN : 0915-1168
ISSN-L : 0915-1168
Volume 64, Issue 12
Special Issue on Tribology Related to Semiconductor Manufacturing
Displaying 1-16 of 16 articles from this issue
Announcement
Contents
Serial Messages to Tribologists
Special Issue on Tribology Related to Semiconductor Manufacturing
Explanation
Up-to-date News Tribo-Episode -Tribo-Technology Award-
Up-to-date News Tribo-Episode -Award for Young Tribologists-
Original Contribution on Science
  • Masanori KOMABA, Shinya KONDO, Atsushi SUZUKI, Kazue KURIHARA, Shigeyu ...
    2019 Volume 64 Issue 12 Pages 740-746
    Published: December 15, 2019
    Released on J-STAGE: December 15, 2019
    Advance online publication: October 22, 2019
    JOURNAL FREE ACCESS

    The effect of temperature on the lubricity of molybdenum dithiocarbamate(MoDTC) and co-additives was investigated by a ball on disk tribometer at temperatures of 25°C, 40°C, 60°C and 80°C. MoDTC was added in polyalphaolefin(PAO) as base oil. Calcium sulfonate(CaSu), calcium borate dispersed in calcium sulfonate(CaBSu), calcium salicylate(CaSa) and calcium phenate (CaPh) were used as a co-additive. In the test with MoDTC alone, the friction coefficient decreased only at 80°C, and the friction coefficient was not stable and fluctuated during the test at 80°C. The friction coefficient became stable with co-additives. The co-additives were classified in two groups on the basis of friction behavior. When CaSu or CaBSu was used as a co-additive, the friction coefficient decreased even at 60°C and 80°C. On the other hand, the friction coefficient decreased only at 80°C with CaSa or CaPh. The results of XPS analysis and HR-TEM observation revealed that MoS2 was formed clearly when the sulfonates were added to the lubricant oil with MoDTC. The behavior of friction coefficient was closely dependent on the kind of co-additives and the oil temperature. As a role of the sulfonate for the MoS2 layer formation, it is thought that sulfonates act as a S source for MoS2 and a binder for the boundary layer.

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Original Contribution on Technology
  • Eita KUREHA, Masayoshi MURAKI
    2019 Volume 64 Issue 12 Pages 747-758
    Published: December 15, 2019
    Released on J-STAGE: December 15, 2019
    Advance online publication: October 22, 2019
    JOURNAL FREE ACCESS

    Lubrication mechanism of the vane-top of multiple vane type compressors was investigated to extract dominant parameters deteriorating oil film formation under high suction pressure conditions leading to abnormal wear of the cylinder inner surface. A calculation model was constructed using coupled analysis of the vane-top part and the vane-slot part, in which the mixed lubrication theory was applied. Of the parameters used for calculation of the oil film thickness, the viscosity of the mixture in which the refrigerant is dissolved in oil and the boundary friction coefficient at the vane-slot part were experimentally obtained, and the force from the back-part of the vane and the action force from the gas pressure inside the compression chamber were obtained based on the theory. The proposed calculation analysis was verified by comparing the calculated results of oil film thickness with the separation degree measured by electrical insulating method on the experiments. Besides, the parametric study of calculation analysis revealed that the causes of poor oil film formation at the vane-top under high suction pressure conditions were the high boundary friction coefficient under the starved conditions and the low refrigerant solution viscosity at the vane-top part.

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