Adhesive wear occurs when two surfaces slide against each other and microscopic material fragments stick, tear, and transfer between them. It often appears as galling, scoring, or material buildup, especially in high-friction metal-to-metal contact.
Cohesive wear, on the other hand, involves the material failing from within — not from surface-to-surface interaction. Internal stresses, fatigue, or thermal cycling can cause cracks or spalling to form and release fragments from the substrate itself.
The key difference is this:
- Adhesive wear starts between surfaces due to adhesion.
- Cohesive wear starts within the material due to internal weakness.
Understanding the mechanism helps determine the right countermeasure — whether it’s reducing surface contact with coatings or improving the material’s structural resilience.