Identification of rheological parameters by the squeezing test

Ceramic paste extrusion is investigated using a squeezing test, which compresses a disk of paste between two parallel plates, one of which is moving at a constant speed. From this test, the two-phase nature of ceramic paste can be evidenced. Liquid migration is observed at low compression speed, resulting in very dry paste at the end of the test. The use of this squeezing test for discriminating paste formulation is illustrated with titanium and aluminium oxide pastes. This test is also a good tool for constructing a two-phase model for paste flow modelling. The paste is composed of a pseudoplastic saturated solid and a Newtonian liquid phase. Model parameters K and m, characterising the saturated solid rheology, and k, filtration coefficient characterising the two-phase interaction, can be identified from runs at low and high compression speeds. (C) 2003 Elsevier Science B.V. All rights reserved.