How to measure wear track from profilometer data
Tribology labs extensively use pin-on-disc tests in order to discern tribological properties of materials and systems. At the end of the test, tribometer gives Friction Force vs Distance data. However researchers have to measure wear track in order to understand wear effects. Some labs use expensive 3D Optical Profilometers (such as this one from ZYGO) to measure wear track. Unfortunately most labs can’t effort these profilometers but they use a profilometer to measure a cross section of wear track. Than researcher can integrate that area and find wear track volume.
Above is a plot generated using contact profilometer of a sample tested using ball-on-disk test. Wear track is between two red dots. In order to calculate wear track area from this data, one must first find the line that crosses from those two red dots at the peaks of wear track. Than using numerical integration calculate area under that line and subtract area under profile data.
Above is the result of that calculation. You can use spreadsheet software for that calculation but it takes time. I’ve written an R package called trib, that is distributed free of charge to calculate wear track area that is faster.
Please feel free to ask me anything on tribology.