Temperature Effect on Shear Flow and Time Dependant Modelling of Cutting Oil Emulsion

The effect of temperature and shear rate on rheological behaviour of cutting oil emulsion was investigated in this work. The model of Herschel-Bulkley was used to fit the shear stress dependence of the shear rate for temperatures between 20°C and 100°C. The temperature increase induced not only a decrease in the yield stress and the consistency index of cutting oil emulsion but also an increase of the flow index of cutting oil emulsion. The temperature dependence of limit viscosity at high shear rate of the cutting oil emulsion was fitted by an Arrhenius equation. For constant shear rate applied on the cutting oil emulsion at 20°C a thixotropic behaviour was observed and analysed using a modified model of Herschel-Bulkley in which a structural parameter λ was included in order to account for time dependent effect.