Kopás

Kopás is a Hungarian term commonly used in engineering to denote wear or abrasion: the gradual removal of material from solid surfaces in relative motion. It can occur in any machine component where surfaces contact and transfer energy, heat, or particles, leading to reduced performance, higher energy consumption, and potential failure if not managed.

There are several forms of kopás, including adhesive wear, abrasive wear, surface fatigue wear, and corrosive wear. Adhesive wear results from metallurgical bonding between asperities that rupture and transfer material to the counterface. Abrasive wear occurs when harder particles or rough surfaces plow or gouge material away. Surface fatigue wear arises from cyclic loading that drives crack initiation and failure of surface layers. Corrosive wear involves chemical or electrochemical attack that weakens the surface in conjunction with mechanical action.

Wear mechanisms depend on operating conditions such as load, sliding speed, temperature, lubrication, material hardness, and environmental factors. Sliding contacts are prone to adhesive and abrasive wear, while rolling contacts may show pitting or spalling as fatigue progresses. Wear rate is often described by volume or mass loss and may be influenced by the presence of protective films, debris, and third-body particles.

Kopás is typically quantified through wear rate or thickness/ mass loss measurements, using laboratory tests such as pin-on-disk or tribological rigs, and through in-service monitoring. Reducing wear involves material selection with higher hardness or wear resistance, surface engineering and coatings, proper lubrication and filtration, temperature control, and design approaches that minimize metal-to-metal contact and misalignment.