Rheological effects of strusture breakdown in semisolid slurries

Abstract

An essential element for the integration of the semisolid metal (SSM) process in the production of complex commercial components is the availability of accurate mathematical and computational tools that could describe both the material characteristics and the dynamics of semisolid slurries during die filling. Computational simulation and modeling is also a powerful and an effective tool that can be used to understand complex physical phenomena, such as those observed with semisolid slurries, and to support theoretical models describing them. We show how important physics can be revealed using experiments combined with numerical simulations. More specifically, we investigate the flow details and the shape evolution during the compression of a finite amount of a Herschel-Bulkley fluid, and the flow of such a material in a rotational viscometer. These two flows relate to popular experiments that are commonly used to determine rheological constants of semisolid slurries. The goal is to use mathematical and computational tools to test postulates for physical and theoretical models used to describe semisolid slurry behavior. The ultimate objective of this work is to contribute to the development of a methodology, which relates simulations to actual experimental results in order to determine the material constants of semisolid slurries.