tribology

Tribology is the science and engineering of interacting surfaces in relative motion. It encompasses friction, wear, and lubrication, and seeks to understand and control the contacts that limit efficiency and durability in mechanical systems. The term tribology was coined in the 1960s by Peter Jost, building on earlier observations by Renaissance and 18th–19th century investigators of friction and wear.

Friction is the resistance to motion between surfaces. Wear is the progressive loss of material due to contact, often accelerated by high loads, heat, and surface roughness. Lubrication introduces a film or layer between surfaces to reduce direct contact and energy loss. Lubrication regimes include boundary, mixed, hydrodynamic, and elastohydrodynamic lubrication, influencing friction and wear. The real contact area is typically much smaller than the apparent contact area and is controlled by surface asperities and material properties.

Tribology spans subfields such as nanotribology, biotribology, geotribology, and marine tribology, and involves experimental, theoretical, and computational approaches. Methods include tribometer tests (pin-on-disk, ball-on-flat), wear-rate measurements, and coefficient-of-friction data, as well as simulations (finite element, molecular dynamics) and surface engineering techniques. Measurement of surface roughness, hardness, and film properties informs models of contact mechanics and lubrication.

Applications range from machine components (bearings, gears, seals) and manufacturing processes to automotive, energy, biomedical implants, and microelectromechanical systems. Effective tribology reduces energy consumption, wear, noise, and maintenance costs, contributing to reliability and sustainability in a wide array of technologies.