A New Machine to Characterize Microstructural Evolution of Semi-Solid Metal Billets through Viscometery

Abstract

The methods to study the "rheological behavior" of semi-solid metal, SSM, slurries are all based on measuring the viscosity. The viscosity is an indication of SSM capability in filling the mould and determines the required force for its deformation and flow. One way to measure viscosity is the application of parallel plate compression viscometery. A new "parallel plate compression machine" for commercial scale is designed, fabricated and tested for viscosity measurement. It is based on monitoring and registering the height changes of the test piece with time. The registered data is treated mathematically to plot strain-time graph from which the viscosity is calculated. The machine is capable of differentiating amongst various SSM microstructures ranging from dendritic to rosette and globular morphologies of the primary phase. © 2006 Elsevier Ltd. All rights reserved.