Archard wear volume / wear coefficient

For further tribology analysis, see TriboSolver; check that the selected model applies to your contact and operating conditions.

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.

Volume versus depth: V is the total removed volume, not a wear depth or scar width. Converting it to a mean depth requires a separately justified worn area; this calculator does not determine that area. L is accumulated relative sliding distance, including every pass in a repeated or reciprocating test.

Worked example

To estimate sliding wear, enter K = 10⁻⁶, normal load W = 10 N, distance L = 1000 m and hardness H = 1 GPa. Archard’s equation gives V = 10⁻¹¹ m³ = 0.01 mm³. The specific wear rate is 10⁻⁶ mm³/(N·m).

For the reverse calculation, select Find wear coefficient and enter measured volume 0.25 mm³ with the same load, distance and hardness. The result is K = 2.5 × 10⁻⁵. Use this coefficient only for comparable material, surface, lubrication and test conditions; it is not a universal material property.