Rheological Behaviour of Liquid ALUHAB Aluminium Foams

The flow characteristic of a new type of aluminium foams is described by high temperature viscosimetry. Rheological measurements were performed on stable foams with cone-plate rheometer. Due to our unique technology stable foams can be produced with different cell size. Foams were produced from various foamable alloy compositions containing different alloying elements and solid particles. Time dependence of aluminium foams was also investigated. Results show a shear-thinning behaviour with a strong dependence of yield stress on bubble size. Below a critical bubble size aluminium foams are stable against shear stress, and show fluid-like flow without degradation. This property allows filling moulds to produce foamed aluminium castings.