Crack growth in pyrographite under the conditions of radiation

The damage induced by radiation in the pyrographite is accompanied by significant plastic deformation. Microcracks arise in the edges of the radiated areas that develop radially in the direction of the unaffected matrix. The peculiarities in the formation of the tension state of the radiated area and adjacent unaffected areas are analyzed in order to explain the reasons behind the growth of cracks. The analysis is carried out on graphite disks with constant thicknesses that are exposed to radiation with high-energy electrons in an HVTEM-JEOL 1000. A differential equation for specific load conditions is obtained from the analysis of equilibrium conditions of a disc-shaped element.