The lubrication performance of polyisobutylene which is used as a lubricant for bolt tightening, was investigated in order to understand the lubrication mechanism during the tightening process. Ball on plate type spinning friction tests were conducted, and three kind of polyisobutylene(PIB-L, M, H) in which the highest viscosity is PIB-H, followed by PIB-M and PIB-L, and polyphenyl ether(5P4E) were used as lubricants in this study. Results show that the friction coefficient of PIB at initial stage of the tests at 400 MPa, depends on the viscosity, and that of PIB-H is the highest in the lubricants. It is also shown the friction coefficient increase with increasing contact pressure, and that of PIB-L, PIB-H and 5P4E at 600 MPa is greater than that of PIB-M. Large wear is observed on the contact surface after the test. In the spinning test, the thickness of entrapment oil film decrease with time, and the decreasing rate in 5P4E is greater than that in PIB-M. These results suggest that the lubrication film formed by PIB-M has an ability to prevent for wear and seizure at the condition with high contact pressure, such as the contact of screw tightening.
|ジャーナル||Toraibarojisuto/Journal of Japanese Society of Tribologists|
|出版ステータス||Published - 2016|
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