Statistical Hypothesis Testing Of the Increase in Wear Debris Size Parameters and the Deterioration of Oil

The effectiveness of lubricant diminishes with use. It also affects the condition of the surface which it is lubricating. Hence characteristics of the wear particles from the surface it is lubricating may change with the condition of the lubricant. This work attempts to investigate the morphological changes of wear particles with the oil degradation and can be helpful in finding the correlation between the two, the age of the oil and the morphology of wear debris. Wear particles from the two gear oil samples at substantial operating time interval were filtered and their images were captured using SEM (Scanning Electron Microscope). These images were binarized and size parameters of these binary images were extracted using blob analysis, using an image analysis software. Increase in these size parameters with oil ageing were investigated by statistical hypothesis testing at 5% significance level. Significant increase in a few parameters of size of wear debris was observed with ageing of oil.