Adhesive phenomena at the alpha -Fe interface during nanoindentation, stretch and shock

The processes of nanoindentation, stretching and shock of alpha -Fe asperity with the (100) and (114) alpha -Fe surfaces are computer simulated at the atomic level by a molecular dynamics technique. Atomistic mechanisms of contact creation during push indentation and contact breaking during the following pull stretch are investigated. The correlation between the structure transformation and the variations of the adhesive bond number, viscosity of contact, energy and force of adhesion is analysed. The crowdion mechanism of plastic deformation under indentation is confirmed. An adhesive model for the strength-differential effect is developed. The adhesive-vibratory effect during the shock of nanoparticles is observed. The acoustic vibrations generated during the shock are shown to transform into inelastic flow, amorphization and fracture of nanoparticles. The resonance principle of powders compacting is proposed.