asperity contact

Asperity contact refers to how two rough surfaces touch each other, not across their entire area but at many tiny peaks called asperities. When two surfaces meet, only these small high points make contact initially, while the valleys and flat areas remain separated. This localized contact affects how much friction there is, how materials wear, and how heat is transferred between surfaces. Understanding asperity contact helps in designing better seals, bearings, and other mechanical components by predicting how surfaces will behave under load and over time.