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Analytical Ferrography Applied to Driveline Fluid Analysis
Abstract:
Analytical ferrography of used oils is most often associated with machine maintenance programs where it is used as a predictive tool to avoid catastrophic failures. The technique is not widely used in driveline fluid evaluations, likely due to both its expense and a general unfamiliarity of the technique among engineers and scientists involved in driveline fluid analysis. However, this technique can provide data essential to understanding the degraded performance of the friction interface.
In this paper we briefly describe analytical ferrography. We then show three circumstances where the use of this technique is appropriate for the evaluation of used driveline fluids. First we illustrate how analytical ferrography can be used to detect the past presence of water in oil that is currently dry. Next we show how the technique can help identify contaminant particles that would normally remain undetected due to size and low abundance. Finally we demonstrate how this technique can be used to identify friction material debris.
We close with an amusing example of an odd-looking contaminant found during a routine oil analysis.