Quantitative methods in wear debris analysis

Wear debris has been recovered from several test systems and analyzed using different methods. These methods produced specific information concerning the particulate size and composition. A magnetic debris recovery method was quantitatively evaluated using debris samples and also using collections of manufactured particulates having known sizes and compositions. Small 5 μm diameter SiO₂ spheres, some containing nickel, were used to simulate debris. Other particulates of iron and nickel in different size ranges were also used in order to investigate such matters as size resolution, lubricant dilution techniques, particle overlap difficulties and the general problem of calibration of debris recovery systems. A comparison between chemical analysis and particulate analysis findings is presented. The application of optical and electron microscope methods and X-ray microanalysis in characterizing the wear particulates was carried out directly on the recovery substrate; these techniques are described.