From Specification to Mechanism: Lessons from Coating Tribology

This presentation argues that progress in coating tribology does not come from reproducing fixed specification values, but from understanding the underlying failure and contact mechanisms. Through several case studies, it shows how conventional specification-driven tests can give misleading or incomplete conclusions when applied outside their original context. Examples include soft polymer coatings on steel, where standard peel and scratch methods fail to detect true adhesion loss; TiN coatings in tribocorrosion, where static corrosion assumptions break down under dynamic sliding conditions; and hard chrome replacement, where matching hardness alone does not reproduce functional performance across different applications. Across these cases, the central lesson is that tribological behaviour is system-dependent, dynamic, and strongly influenced by the interaction between material, environment, and loading conditions. The presentation advocates a mechanism-based pathway for innovation: start from the real failure mechanism, reproduce it at laboratory scale, validate the method, and only then develop standards or specifications. For researchers, engineers, and policy makers alike, the message is clear: sustainable coating development and substitution require functional redesign rather than metric replication.