A Model for Shear Degradation of Lithium Soap Grease at Ambient Temperature

Yuxin Zhou, Rob Bosman, Pieter Martin Lugt

    Research output: Contribution to journalArticleAcademicpeer-review

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    Abstract

    In this paper the shear degradation of lithium 12-hydroxy stearate grease will be measured using an in- house-developed Couette aging machine. In this device the shear rate is well defined. The aging is related to the generated entropy density, as described in Rezasoltani and Khonsari’s work (Tribology Letters, Vol. 56, No. 2, pp. 197–204, 2014 and Ref. 11). The rheological properties of the aged samples were evaluated using a parallel-plate rheometer. The results showed that there are two aging phases with different degradation rates, i.e.—a progressive degradation phase at the early stage, followed by a rather slow deterioration afterwards. Based on this observation an aging equation was
    formulated to describe the aging behavior of lithium-thickened grease. Atomic force microscopy results of the fresh and aged greases showed that the variation in thickener microstructure provides a good explanation for the lithium grease degradation mechanism; under shear, the original fibrous network is progressively destroyed and becomes fragmented, leading to the loss of consistency and a change in the rheological properties.
    Original languageEnglish
    Pages (from-to)38-46
    Number of pages9
    JournalPower Transmission Engineering
    Volume11
    Issue number7
    Publication statusPublished - 2017

    Fingerprint

    Soaps (detergents)
    Lubricating greases
    Lithium
    Aging of materials
    Degradation
    Temperature
    Tribology
    Rheometers
    Shear deformation
    Deterioration
    Atomic force microscopy
    Entropy
    Microstructure

    Cite this

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    title = "A Model for Shear Degradation of Lithium Soap Grease at Ambient Temperature",
    abstract = "In this paper the shear degradation of lithium 12-hydroxy stearate grease will be measured using an in- house-developed Couette aging machine. In this device the shear rate is well defined. The aging is related to the generated entropy density, as described in Rezasoltani and Khonsari’s work (Tribology Letters, Vol. 56, No. 2, pp. 197–204, 2014 and Ref. 11). The rheological properties of the aged samples were evaluated using a parallel-plate rheometer. The results showed that there are two aging phases with different degradation rates, i.e.—a progressive degradation phase at the early stage, followed by a rather slow deterioration afterwards. Based on this observation an aging equation wasformulated to describe the aging behavior of lithium-thickened grease. Atomic force microscopy results of the fresh and aged greases showed that the variation in thickener microstructure provides a good explanation for the lithium grease degradation mechanism; under shear, the original fibrous network is progressively destroyed and becomes fragmented, leading to the loss of consistency and a change in the rheological properties.",
    author = "Yuxin Zhou and Rob Bosman and Lugt, {Pieter Martin}",
    year = "2017",
    language = "English",
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    journal = "Power Transmission Engineering",
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    A Model for Shear Degradation of Lithium Soap Grease at Ambient Temperature. / Zhou, Yuxin ; Bosman, Rob ; Lugt, Pieter Martin.

    In: Power Transmission Engineering, Vol. 11, No. 7, 2017, p. 38-46.

    Research output: Contribution to journalArticleAcademicpeer-review

    TY - JOUR

    T1 - A Model for Shear Degradation of Lithium Soap Grease at Ambient Temperature

    AU - Zhou, Yuxin

    AU - Bosman, Rob

    AU - Lugt, Pieter Martin

    PY - 2017

    Y1 - 2017

    N2 - In this paper the shear degradation of lithium 12-hydroxy stearate grease will be measured using an in- house-developed Couette aging machine. In this device the shear rate is well defined. The aging is related to the generated entropy density, as described in Rezasoltani and Khonsari’s work (Tribology Letters, Vol. 56, No. 2, pp. 197–204, 2014 and Ref. 11). The rheological properties of the aged samples were evaluated using a parallel-plate rheometer. The results showed that there are two aging phases with different degradation rates, i.e.—a progressive degradation phase at the early stage, followed by a rather slow deterioration afterwards. Based on this observation an aging equation wasformulated to describe the aging behavior of lithium-thickened grease. Atomic force microscopy results of the fresh and aged greases showed that the variation in thickener microstructure provides a good explanation for the lithium grease degradation mechanism; under shear, the original fibrous network is progressively destroyed and becomes fragmented, leading to the loss of consistency and a change in the rheological properties.

    AB - In this paper the shear degradation of lithium 12-hydroxy stearate grease will be measured using an in- house-developed Couette aging machine. In this device the shear rate is well defined. The aging is related to the generated entropy density, as described in Rezasoltani and Khonsari’s work (Tribology Letters, Vol. 56, No. 2, pp. 197–204, 2014 and Ref. 11). The rheological properties of the aged samples were evaluated using a parallel-plate rheometer. The results showed that there are two aging phases with different degradation rates, i.e.—a progressive degradation phase at the early stage, followed by a rather slow deterioration afterwards. Based on this observation an aging equation wasformulated to describe the aging behavior of lithium-thickened grease. Atomic force microscopy results of the fresh and aged greases showed that the variation in thickener microstructure provides a good explanation for the lithium grease degradation mechanism; under shear, the original fibrous network is progressively destroyed and becomes fragmented, leading to the loss of consistency and a change in the rheological properties.

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    JF - Power Transmission Engineering

    SN - 2331-2483

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