The adhesion of clean metals

摘要: This paper describes a study of the adhesion between metallic surfaces which have been denuded surface films by heating in high vacuum (about 10$^{-5}$ $\mu $). Earlier experiments shown that when two very soft metal specimens are pressed together they adhere strongly, but these results past often considered anomalous. The present work shows harder metals also on contact, although low values normal recorded after pure loading, even denuded. apparent lack is attributed to influence released elastic stresses, may break many bridges formed asperities as soon load removed. If conditions such can extend ductile manner and so accommodate recovery, junction retain its full strength. measured then equal original load. found for indium at room temperature other enough allow anneal. When tangential force applied loaded area contact be increased plastic flow under combined enhanced strength obtained. Adhesion coefficients well over 10 temperature. A simple extension junction-growth theory proposed McFarlane & Tabor takes account recovery applicable generally. close relationship friction apparent.