Mechanics of high strength and high ductility materials

Abstract

The ability to create structural materials of high yield strength and yet high ductility has been a dream for materials scientists for a long time. This paper will summarize the recent work related to the study of the mechanical behavior of the surface nanostructured materials using SMAT (Surface Mechanical Attrition Treatment). Significant enhancements in mechanical properties of the nanostructured surface layer in different materials will be analyzed. The effect of surface nanostructures on the mechanical behavior and on the failure mechanism of metallic material shows the possibility to develop a new strength gradient composite. The nanoindentation method is developed for the investigation of the gradient structures. The role of the residual stress is studied. The results shown that the compressive residual stress is one of the key mechanisms for the enhancement and the extraordinary properties of layered nanostructured metallic stainless steel sheet. Finally, some new results of the simulations will be presented and discussed. The simulation of SMAT process using the finite element methods will be compared with the experimental investigation using high speed camera. The computational models successfully simulate the enhanced ductility and strength and provide valuable information about the mechanical behavior of nanostructured layered composite material.