Hankauksen

Hankauksen is the Finnish term for abrasion or wear caused by rubbing between surfaces. In tribology, hankaus describes material loss or surface deformation produced by sliding contact, including two-body and three-body abrasion. In two-body abrasion, a hard counterface or asperities directly remove material from a softer surface; in three-body abrasion, loose particles between surfaces cause wear.

Mechanisms commonly involved are adhesive wear, abrasive wear, and surface fatigue from repeated stress cycles. Frictional heating can accelerate wear, especially at higher speeds or under poor lubrication. Wear is typically described by wear rate and, in engineering contexts, by Archard’s wear law, which relates wear volume to load, sliding distance, hardness, and a dimensionless wear coefficient.

Causes of hankaus include insufficient lubrication, high contact pressure, high sliding speeds, and the presence of abrasive particles or corrosive environments. Material properties such as hardness, toughness, and microstructure also influence susceptibility to wear.

Prevention and control strategies cover lubrication optimization, the selection of harder or more wear-resistant materials, surface hardening, and protective coatings (for example, ceramic coatings or diamond-like carbon). Design approaches that reduce contact pressure, improve surface finish, or minimize the presence of abrasive contaminants are also effective. Regular maintenance and proper operating conditions further reduce wear rates.

Applications of hankaus concepts span mechanical engineering and technology, including automotive components (bearings, gears, brakes), manufacturing tools, and various consumer devices. The term is also used in biomechanics and dentistry to describe friction- and wear-related phenomena on articulating surfaces.

Etymology: the word derives from the Finnish verb hankaa, meaning to rub or scrape.