The results of the study of radiation-induced strengthening and microstructure evolution in the 0Kh18N10T austenitic stainless steel irradiated by neon ions (with energy of 230 MeV) and neutrons (En > 0.1 MeV) are presented. The experiments were performed in an inner beam of an U-400 cyclotron in Dubna and in an EWA reactor (Institute of Atomic Energy, Swerk, Poland). The dependence of the mechanical properties on the dose of irradiation-induced damage was determined. Changes in microstructure are studied by TEM, and the density of the aggregates of irradiation-induced defects was determined as a function of the dose. The data obtained are discussed in terms of mechanical properties and microstructure characteristics.
Self-propagating thermal waves of the amorphous-crystalline transformation in Fe-based metallic glasses, obtained by melt spinning, were observed using a high-speed infrared camera and reported here. Some experimental results are also reported concerning oscillating waves in the CuTi glassy foils. The thermal characteristics and wave propagating velocities, as well as the microstructure and atomic structure transformations, were studied. A comparison of the results with exothermic reaction waves and explosive crystallization shows that the self-propagating waves in metallic glasses are slower and less violent than classical explosive crystallization in deposited films; thus, we suggest naming this phenomenon “soft explosive crystallization.” The experimental data were confirmed by molecular dynamics simulation of the crystallization phenomenon.
The multicomponent nitride coatings from TiZrNbAlYCr high entropy alloy (HEA) were fabricated using the vacuum-arc method. The effect of nitrogen pressure on the crystallite size, elemental and phase composition of (TiZrNbAlYCr) N coatings was investigated. A bias voltage applied to the substrate during the deposition process was -200 V. The partial nitrogen pressure was 0.05 Pa, 0.27 Pa, and 0.5 Pa. Body-centered cubic (BCC) lattice with crystallites of 15 nm in size was formed at the lowest pressure. An increase in the pressure led to the formation of the two-phase structure: BCC phase with crystallite size of 15 nm and face-centered cubic (FCC) phase with crystallite size of about 3.5 nm. The same two-phase state was found in coatings fabricated at 0.5 Pa, while the mean crystallite size was 7 nm. The maximum hardness of the deposited coatings was about 47 GPa.