Modifications in Microstructure, Deformation and Fatigue Behavior by Ion Implantation

摘要

A number of materials, copper, aluminum, titanium and steel, have been examined for microstructural evolution, deformation and fatigue behavior in the ion implanted, as - implanted and implanted + annealed conditions. A wide variety of implant species that produce residual compressive stresses, residual tensile stresses or cause precipitation have been chosen to examine the above effects. The main goal has, however, been to choose implant species that would enhance deformation and fatigue resistance through a modification in the surface microstructure and/or by providing residual compressive stresses. In instances where no major changes in the surface microstructure are observed it appears that surface dislocation sources either become inoperative or become operative on a larger number of slip planes, limiting the size of the slip steps that would nucleate fracture. In materials where major changes in the microstructure are observed, slip is dispersed, also resulting in fine slip that enhances resistance. Ion implantation is being used to modify surface-related mechanical properties such as friction and wear, fatigue, corrosion and recently, near surface deformation at high temperatures.