Rheological analysis of ceramic pastes

This paper is concerned with a number of means of characterising the rheolo gical properties of a ceramic paste. The intrinsic flow behaviour of the pa ste, during upsetting, is studied experimentally by using multi coloured pa ste samples, as well as by a finite element numerical computation. The flow behaviour of the paste is approximated by an elasto-viscoplastic material constitutive model and implemented by using an established finite element c ode. The material flow properties, which are necessary for the implementati on of the numerical model, were obtained using the squeeze film and hardnes s indentation test configurations. The flow fields generated by the simulat ion are shown to be a good accord with the experimental observations. The e xperimental procedure for selecting the material parameters which are neces sary for the implementation of the numerical model is described. The accura cy of the numerical method described is also evaluated by comparing the sim ulation results with experimental data obtained from the net upsetting forc e against the imposed relative displacement behaviour and the flow visualis ation of deformed coloured layers. In these respects, a comparison of the f inite element model predictions and the experimental results demonstrates a good mutual agreement. (C) 1999 Elsevier Science Ltd. All rights reserved.