COMPUTER SIMULATION OFHOT SOLID-PHASE PRESSINGOF COMPOSITE POWDERMATERIALS BASED ONPOLYTETRAFLUOROETHYLENE

structured material is presented. An important point of this theoretical description is the consideration of the dependence of viscosity on temperature, density of the compressed material and structural parameter. Physical concepts of material deformation under external loads as a process of structural transformations similar to a chemical reaction occurring in the forward and reverse directions (destruction and restoration of the structure) are used. A feature of the proposed structural approach is the interconnected consideration of the rheodynamics of viscous systems with the process of structural transformations. New visual concepts of the kinetics of non-isothermal compaction of powder materials based on polytetrafluoroethylene with various additives in various pressing modes are established: constant pressure or press plunger speed. It is shown that for pressing materials in both modes, such parameters should be selected when the time of structural transformations is longer than the compaction time. The analysis made it possible to develop specific recommendations for predicting rational modes of one-sided pressing of powder materials.