Sintering is a complex physical and mechanical process, which is one of the most
important technological processes in powder metallurgy and ceramic industry. In this paper,
the study of free sintering of a ceramic object is carried out using the rheological theory of
sintering. Numerical solution of the problem in the three-dimensional case is implemented using
the Finite Element Method with the freely distributed FreeFem++ software. Experiments on
sintering of aluminium oxide ceramic paste were conducted for several temperature regimes.
The validation of the realized model is confirmed by comparing the numerical and experimental
data of porosity evolution.