Numerical simulation of HPT processing

Abstract

The principle of achieving high strength and superior properties in metal alloys through the application of severe plastic deformation has been exploited in the metal processing industry for many decades. In this contribution finite element simulations are presented of the HPT process. As opposed to most studies in literature, in which rigid sample holders are considered, the real elasto-plastic behavior of the holders is modeled. The simulations show that during the compression stage, plastic deformation occurs in the holders: initially, at the outside boundary of the sample cavity and, at a later stage, underneath the centre of the sample. The latter region of plastic deformation is rapidly growing and has a non-negligible effect on the response of the sample. Major conclusion is that the sample holders, and more specific, their deformability is key for the conditions in the specimen. Indeed, it severely affects important parameters for both the microstructural changes in the sample material, such as the amplitude and distribution of the hydrostatic stress, and its final shape. © Published under licence by IOP Publishing Ltd.