Surface forces, deformation and adherence at metal microcontacts

Abstract

The role of surface forces on deformation and adherence of metal microcontacts is reviewed. Plastic deformation under zero applied load is discussed. After an elastoplastic or full plastic contact under a load P giving a radius of contact a ƒ , the separation can be either ductile ( F d mode) at a tf , or brittle at a tf ( F m mode) or at a' c < a ƒ(F b mode). A diagram is given, showing the condition of existence of each mode as a function of the five parameters involved (Young's modulus, elastic limit, surface energy, radius of curvature and load). Loading-unloading curves are predicted and compared with the literature data.