What volume and area measurement tells you
Wear, corrosion, erosion, machining, deposition and drying all move material. Volume measurement says how much; area measurement says how much surface there really is. Both come from the same 3D map, by integrating height above or below a reference.
Wear-track volume and wear rate
The most common use is wear testing. Standards such as ASTM G99 and G133 report wear as volume loss, and the specific wear rate K = V / (F × s) needs that volume. A 3D profile of the wear track gives it directly, along with the track depth and width and any material piled up at the edges. NANOVEA’s published tribology studies use profilometry for exactly this. In the polymer belt study, for example, the integrated profiler on the T2000 measured 75.7 mm³ and 14.0 mm³ on two belts.
Weighing struggles here. Hard coatings lose too little mass to weigh reliably, and polymers absorb moisture. Volume from profilometry avoids both problems.
Measuring wear on the tribometer
On the T2000, the profiler can be integrated on the tribometer itself. The sample is never removed, so the track is measured in exactly the same place each time and can be re-measured at intervals during a test. NANOVEA’s progressive wear mapping study used this to follow flooring wear across seven test cycles, connecting friction data to the wear rate at each stage.
Surface subtraction
When there is no clear original surface to reference, such as general corrosion, erosion of a shaped part or polishing, two maps of the same area can be aligned and subtracted. The difference map shows exactly where material was lost or gained, and its integral gives the volume.
Voids, material and developed area
Volume analysis also describes the surface itself:
- void and material volume above or below a given height, and the mean thickness of each, used for lubricant retention, porosity and bearing capacity;
- area above or below a height, in percent or µm²;
- developed versus projected area, the true surface area relative to its footprint, which drives adhesion, coating uptake, wetting and catalysis.
Grains and motifs
Segmentation divides the surface into discrete features (grains, pores, bumps, dimples, motifs) and reports their number, size, area, perimeter, height, volume and pitch. NANOVEA’s surface boundary study combined topography with reflected intensity from the same scan to separate Styrofoam beads from their boundaries.
