Cold extrusion of severely plastic deformed high-strength materials

摘要

Due to the recent market-driven requirement to reduce the weight of parts and simultaneously the cost of materials, the development of high-strength .engineering materials is increasingly gaining importance in the last decades. Ultrafme grained (UFG) materials produced by severe plastic deformation (SPD) processes have outstanding mechanical properties such as a combination of high strength and high ductility, which makes these advantageous for the lightweight applications. In the present paper, a novel SPD process, "Equal Channel Angular Swaging" (ECAS), will be introduced. Tribological and mechanical properties of two plain carbon steels, C4C (1.0303) and C15 (1.0401) processed by ECAS, as well as the effect of these properties on the reprocessing of the same materials by extrusion are investigated before and after severe plastic deformation. The investigations prove that the severe plastic deformation does not have an effect on the tribological properties of the investigated materials. Moreover, the reprocessing of both severely plastic deformed materials, C4C and C15, is possible by extrusion. The hardness distribution in the ECAS samples is more homogenous than in the as-received material and the hardness values are higher. Therefore, ECAS-processed materials have a high potential for lightweight applications.