{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"ef8565da48f72fa53ecc5c041e6d6465f15c50569595528b26596e032afe57e1","created":"2026-10-03T07:17:57Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"be9952218b5fdd37dbf00e7392471454c7ff317ec53d010984483ac4b7bc296f","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"bio.friction-wear.archard-wear-law","kind":"phenomenon","literature_status":"partially-resolved","n":"1","parents":[],"plain":"The amount of material lost by wear grows in proportion to load and sliding distance, but the proportionality constant varies by a factor of a million between materials and cannot be predicted. Its link to what happens at single contacts is unclear.","posed_since":"","precise":"Archard's law $V = K N s / H$ (wear volume V, load N, sliding distance s, hardness H) has an empirical dimensionless coefficient K spanning roughly $1e-8 \\text{ to } 1e-2$. Derive K from asperity-scale mechanisms, including the critical junction size $d*$ proportional to $G w / \\tau_j^{2}$ (shear modulus G, surface energy w, junction strength $\\tau_j$) below which junctions deform plastically instead of shedding debris, and predict wear rates for specified material pairs.","problem_ref":null,"references":"","settled_by":"A multiscale theory predicting K for several metal and ceramic pairs that matches measured wear rates without adjustable parameters.","status_note":"Atomistic simulations since 2016 identify a critical junction size for debris formation; quantitative prediction of K for real surfaces is lacking (2026).","title":"Microscopic basis of Archard's wear law","topic_ref":"dda1bf26b56de68ff6e0bc9fd1289af1a90b0889469abd062648a7c0948252d9"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"ff41ca193e419a66836cc711a7642fea0cbe071ce55e7243b2bc9770312e93a5","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"52d7e39553a3245980324b5a6c18cd28dd406ce4ad24da46c96031adadfba9e3","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"eakAaVRwec00zg-yizDGhQ7pfz5ZNN3rQiYyys-dSrxBFlYdZJ9hvKnxgt8w7nsBdmmpL3Uu-XaAj1TlaLCQCQ"},"schema":"pubphys.envelope/1"},"record_hash":"ff41ca193e419a66836cc711a7642fea0cbe071ce55e7243b2bc9770312e93a5","leaf_index":773}