The effect of ion irradiation (Ar⁺, E = 15-20 keV) on the microstructure of the deformed Ni - 13.9 Wt.% W alloy

Using X-ray diffraction analysis, the effect of Ar⁺ ions with an energy of 15-20 keV (at ion current densities of 100-300 μA/cm²) on the microstructure, the level of internal microstresses and the texture of cold rolled ribbons of alloy Ni-13.9 wt.% W was studied. It was found that short-term irradiation of 80 μm thick ribbons with a fluence of 3.1·10¹⁶ cm^-2 (for 50 s) at temperatures T ≤ 370°C and T = 630°C leads to a decrease in microstresses in their entire volume, but at the same time the original texture is retained. With an increase in the fluence to 9.7·10¹⁷ cm^-2 at T = 630°C, the texture also changes from (220) to (200). Changes in microstresses and texture on the irradiated and unirradiated sides of 80-μm-thick ribbons are comparable to each other, despite the fact that the projective range of Ar⁺ ions with an energy of 15-20 keV in the alloy is only ~7 nm. It is known that annealing in an oven (700°C, 30 min) of such ribbons does not lead to their recrystallization. At 850°C, microstresses are relieved and the texture drastically changed from (220) to (200) both as a result of annealing in a furnace (15 s) and as a result of irradiation with a fluence of 3.2·10¹⁶ cm^-2 for 17 s, but the effect removal of stresses in the course of furnace annealing is 3 times lower than in the course of irradiation. Thus, the following facts have been established: 1) the occurrence of recrystallization processes in the alloy under study during irradiation at a temperature lower than the temperature of the onset of thermally activated recrystallization and 2) a higher rate of microstresses drop (and to lower values) in the course of irradiation than during furnace annealing. This indicates a significant role of nanoscale radiation-dynamic effects at the cascade-forming irradiation of metastable media.

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