{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"c6e8807b440edacc0f14ec90d26be5144d46e3fb0b03c627721dac17abb97766","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","ff41ca193e419a66836cc711a7642fea0cbe071ce55e7243b2bc9770312e93a5"],"salt":"eede41120a64f8aba84f1fcb5660d5ccf59060144a8dbb45e32ccc71c621185a","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":"2","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 $10^{-8} \\text{ to } 10^{-2}$. 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":"ff41ca193e419a66836cc711a7642fea0cbe071ce55e7243b2bc9770312e93a5","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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"6335aa3b04596286685a47deb60ee394c881695553c6ab120c277f268e631760","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"9c7748527fac3360de0fe50c03e364634ea9108b722960f754465e53e9c0626b","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"gzB8TBjKTzDOyj1gLe4F78S_Fw8a8esrwFbER-1ZdOPeHEoZWuiNM5Tyj0bV0ykpjBjsDjHn72DoN9r4XLMyCg"},"schema":"pubphys.envelope/1"},"record_hash":"6335aa3b04596286685a47deb60ee394c881695553c6ab120c277f268e631760","leaf_index":2564}