Аннотация
The results of pilot and analytical researches of the stress condition diagram near the pellet ends upon its pushing out from the mold after compaction to reveal the causes of crack formation are presented. It is shown that free surfaces can appear on the green pellet end from the lower punch, due to which a dangerous boundary between the loaded and unloaded parts of a green pellet can be formed which can lead to cracking at certain compacting procedures. The numerical investigations for establishing the maximal shear stresses in a green pellet upon pushing out according to standard regulations and with counterpressure are performed. A technical proposal on the expediency of using the counterpressure upon pushing out after compacting the pellets from uranium dioxide powders is substantiated. It is established that the application of counterpressure excludes the formation of end cracks in green pellets in a wide range of compaction pressures and with the use of various binders and opens up prospects for compacting powders without binders and green pellets without chamfers.