The experimental verification of the known flow line models describing local flow during ECAE (ECAP)

Abstract

In spite of the existence of a number of studies suggesting various models of flow-lines during ECAE, there are few studies dedicated to the experimental visualization of the empirically observable flow-lines. The present research is focused on an experimental verification of the known previously published research results by Han et al (2008), Hasani et al (2008) — Hosseini et al (2009), and Tóth et al (2004) for material flow lines through a die of classical Segal geometry. The experimental research used physical simulation techniques to visualize moving marker trajectories in the vicinity of the channel intersection zone during ECAE of plasticine models. The successive positions of moving markers were recorded with a digital camera with further recognition and digitalization of experimental marker trajectories. This research has shown that experimental flow-lines do not fully fit Toth et al’s and Han et al’s flow models. It was found that the best fit of experimental flow-lines is achieved by using of Hasani et al’s — Hosseini et al’s model. Experimental / theoretical results which were obtained in the current study are of interest to the interdisciplinary SPD mechanics sphere. The experimental verification of the earlier published models quoted in the paper provides the succession, sustainability and academic integrity of the experimental / theoretical results from the SPD mechanics of the various schools of sciences. New results of the study relate to the experimental visualization of the moving markers positions during ECAE physical modeling and the experimental / theoretical determination of corresponding empirical flow-lines.