Increasing stable deformation by declining temperature during the process

Abstract

AbstractRecently increasing amount of light metal sheets, especially based on magnesium, is being involved into various structural constructions and functional components. Such a rising trend can be observed, for instance, at automotive, aerospace and electronic industry. On the other hand there exist some processing difficulties, such as forming limits, caused by crystalline structure.To make processing of magnesium materials most reasonable with a maximum economical and material’s effect, detailed investigation of the material’s mechanical behavior is necessary to realize. Especially, an use of superplasticity is a point of the main interest. By optimum settings of the deformation process (especially temperature and strain rate) the superplastic conditions were determined optimally. Moreover, it was discovered that variable temperature very positively affects the superplasticity of magnesium materials. Actually by changing temperature conditions during the deformation, even higher level of superplastic deformation without rupture can be obtained. This very interesting fact was observed at the elevated temperatures that decrease almost constantly during the deformation process.Thus previously widely used constant temperature treatment opens door to the dynamic problems of searching for the optimal temperature gradient and its variation.