Archard wear volume / wear coefficient

The Archard wear equation is an empirical sliding-wear relation. It states that wear volume is proportional to normal load and sliding distance, and inversely proportional to hardness. In common form, V = KWL/H.

The coefficient K is not a universal material constant. It captures the probability and severity of material removal for a material pair and operating condition, so it should be fitted or compared using representative tests.

• Hardness is usually taken for the softer contacting material or effective near-surface layer.
• For a measured wear volume, the rearranged form K = VH/(WL) gives a dimensionless coefficient for that test.
• Specific wear rate is also reported as V/(WL) in mm3/(N m), a common wear-test reporting metric.
• Sources: TriboNet Archard wear equation article, DoITPoMS Archard equation derivation, and STLE TLT Cutting Edge article on wear-coefficient notation.