Simple shear extrusion was designed in 2009 as a novel severe plastic deformation technique to obtain ultrafine-grained materials. During the past years, extensive work has been done to introduce and clarify this technique's characteristics and investigate its application in different areas of materials science and engineering. Owing to the inherent phenomenon of strain reversal associated with this technique and different available processing routes, this method is proven to be useful in material processing. This article aims to summarise the ability of this process to produce ultrafine-grained materials and discuss the potential of this process for industrialisation.

In this investigation, the previously proposed phenomenological model in the literature is generalized both in terms of the mathematical form of the model and the yield function used to describe the plasticity of the material. Al 1050 is chosen as the model material, where the sheets made from this material are first annealed and then subjected to a tensile test and Erichsen cupping test to obtain tensile properties as well as the FLC of the material. The constants of the generalized model are first obtained by curve fitting, whereby in this approach least overall error is expected as a single equation is used to predict the FLC of material. Further, it is shown that it would be possible to enhance the accuracy of the model at the cost of losing the applicability of a single mathematical expression for both branches of FLC. In this approach, the generalized model would be calibrated for the right branch based on Swift’s model and for the left branch based on Hill’s model. Finally, the effect of the yield criterion used to describe the plasticity of the material on the predictions of the generalized model is investigated, and it is shown that using the Hosford yield criterion yields better results compared to using the von Mises yield criterion.

No abstract

No abstract

The main focus of this investigation is to quantitatively analyze the opposing effect of filler on the desired properties of fabricated composite specimens. First, the high‐density polyethylene (HDPE) powders with proportions of 0, 2, 4, 6, 8, and 10 wt% of boron nitride (BN) are mixed by the ball mill processes and further hot molded to fabricate HDPE‐BN composites. The density and thermal conductivity of fabricated composites are then measured, and the variation of these properties with the added volume percent of BN is determined. The notions of multi‐objective optimization are employed to obtain the optimum BN content to maximize thermal conductivity while minimizing density. The relative importance of these properties is calculated by applying the entropy method to the variation of thermal conductivity and density with the BN content. It is observed that the positive effect of BN on the thermal conductivity has potentially the same importance as its negative effect on the density. In a more general consideration, various hypothetical fillers with a wide range of thermal conductivities and densities are studied by the same procedure. It is obtained that density has a more determinative rule in the efficiency of a particular filler in circumstances where both thermal conductivity and density have practical importance. While the results of this investigation are presented in terms of thermal conductivity and density, the procedure used here can be applied to any set of properties with practical significance.