The relationship between structural change of thickeners and rheological properties on lubricating grease

Michita Hokao, Kentaro Sonoda, Joichi Sugimura

Research output: Contribution to journalArticle

Abstract

Lubricating grease shows the typical rheological properties, such as yield stress, shear thinning and thixotropy. These properties are believed to be originated by changes of thickener structure of grease, though the relationship between the structural change and grease rheology is not fully understood. This study investigates this relationship using lithium 12-hydroxy stearate greases and lithium stearate greases with different thickener concentration, penetration, base oil type, and prototype methods. Rheological property with two pre-shear conditions was evaluated, and thickener structure of greases were observed using an optical microscope, SEM and AFM. Orientation of thickeners and dispersion of thickener aggregations induced by shear were observed using AFM. In addition, it is shown wettability of base oil on thickeners depends on thickener types.

Original languageEnglish
Pages (from-to)42-54
Number of pages13
JournalToraibarojisuto/Journal of Japanese Society of Tribologists
Volume64
Issue number1
Publication statusPublished - Jan 1 2019

Fingerprint

thickeners
greases
Lubricating greases
Stearates
stearates
Lithium
Oils
lithium
oils
thixotropy
atomic force microscopy
shear
shear thinning
Shear thinning
wettability
optical microscopes
Rheology
rheology
Yield stress
Wetting

All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

Cite this

The relationship between structural change of thickeners and rheological properties on lubricating grease. / Hokao, Michita; Sonoda, Kentaro; Sugimura, Joichi.

In: Toraibarojisuto/Journal of Japanese Society of Tribologists, Vol. 64, No. 1, 01.01.2019, p. 42-54.

Research output: Contribution to journalArticle

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