Electron-microscopic study of helium distribution in high nickel alloy

The method of transmission electron microscopy has been used to investigate the development of microstructure in multicomponent alloyed nickel alloy of the 20-45 type under 40 keV helium ion irradiation. Radiation doses were (1-10)x1021 ion/m2, the temperature did not exceed 370 K. It is shown that at D > 3x1021 ion/m2 in the material structure an ordered ensemble of small voids is formed and at the dose 1x1022 ion/m2 they can form a superlattice. The parameter of the void superlattice determined by additional diffraction reflexes near the central spot constitutes 50 A and thier average diameter is 15 A. The void density is maximum in the superlattice and reaches approximately 1025 m-3. The voids can be observed in the cap as well as in bases of blisters