What Does Ferrography Mean?
Ferrography is the study of ferrous metal wear, and comes from the Latin word "ferrum," which translates to "iron."
Ferrography is a technique for analyzing the particles present in fluids that indicate mechanical wear. It has been in use since 1970, and provides microscopic examination and analysis of debris (particles) found in lubricating oils.
Ferrography can be used in laboratory testing for:
- Lubricants and engines
- Evaluating oils
- Predicting lubricant failure
- Studying lubricant wear debris
Corrosionpedia Explains Ferrography
Ferrography is a technique that is used to monitor for wear modes that are undetectable to spectroscopy. It is used to predict and diagnose equipment problems. It is a series of laboratory tests used to determine the condition of used lubricants and equipment components, over a period of time.
By monitoring particles generated by wear or environmental contamination, ferrography experts are able to detect critical stages of accelerated wear that precede costly and dangerous component failures. A ferrographic analysis determines the number, size and shape of wear particles.
Two ferrographic techniques have been developed to monitor the levels of wear particles in lubricated systems:
- Direct-reading ferrography - Gives a direct measure of the amount of ferrous wear metals present in a sample of oil
- Analytical ferrography - Allows an analyst to visually examine wear particles present in an oil sample
Analytical ferrography is the most powerful oil analysis diagnostic tool in tribology. When implemented correctly it provides tremendous information on machines in operation. However, it is frequently excluded from oil analysis programs because of its comparatively high price and a general misunderstanding of its value.
Ferrography has advanced as one of the premier predictive maintenance and analytical tools. This technique for wear particle analysis has become prominent in the paper industry, industrial plants with automated operations and in health care with artificial joints and limbs. In the hands of a skilled analyst, ferrography is capable of detecting active machine wear and can often provide a "root cause" based on the morphology of the wear particles.