Finite element simulation of sintering process (2nd report, constitutive equation for sintering and prediction of shape of sintered products)

A constitutive equation for sintering is proposed. The sintering is described as the deformation process of viscous porous materials under the action of sintering stress, the virtual hydrostatic stress produced by the surface tension. The parameters for the constitutive equation are determined from the experimental results on the sintering of glass powder. The proposed constitutive equation is applied to the prediction of the deformation behavior of glass powder compacts during sintering using the viscoplastic finite element method. The effect of powder particle size on the shape of the sintered body is examined. The sintering rate of the glass powder compact composed of small particles is high and the shape of the sintered body is not significantly affected by its own weight. The predicted shapes of the sintered bodies show good agreement with those obtained by experiment.