FEATURES OF THE STRUCTURAL PHASE STATE OF A FILM BASED ON A HIGH-ENTROPY AlNbTiZrCu ALLOY SYNTHESIZED BY DEPOSITION OF A MULTIELEMENT METAL PLASMA

В данной работе приведены результаты структурных исследований пленок толщиной до 5 мкм высокоэнтропийных сплавов системы AlNbTiZrCu . Пленки были синтезированы на металлических и металлокерамических подложках путем осаждения многоэлементной металлической плазмы, созданной электродуговым плазменно ассистированным одновременным независимым распылением нескольких катодов. Показано, что пленки являются слоистым материалом и имеют аморфнокристаллическую структуру. Установлено, что облучение пленок импульсным электронным пучком (18 кэВ, 20 Дж/см, 50 мкс, 3 имп., 0,3 с) сопровождается кристаллизацией материала. Показано, что в полученных пленках доминирует соединение состава AlNbTiZr с параметром решетки 0,32344 нм. На основе теоретических расчетов получены структурные данные кристаллической решетки AlTiZrNb и определены механические и термодинамические характеристики этого соединения. This paper presents the results of structural studies of films with a thickness of up to 5 microns of high-entropy alloys of the AlNbTiZrCu system. The films were synthesized on metal and cermet substrates by deposition of a multielement metal plasma created by electric arc plasma assisted simultaneous independent sputtering of several cathodes. It is shown that the films are a layered material and have an amorphous-crystalline structure. It was found that irradiation of films with a pulsed electron beam (18 keV, 20 J/cm, 50 gs, 3 imp., 0,3 s) is accompanied by crystallization of the material. It is shown that the resulting films are dominated by the compound of the AlNbTiZr composition with the lattice parameter of 0,32344 nm. On the basis of theoretical calculations, the structural data of the crystal AlTiZrNb lattice were obtained, mechanical and thermodynamic characteristics of this compound were determined.

Plasma Nitriding Mechanisms of Low-Density Sintered Metal Products

The mechanism of plasma nitriding include the formation of various active species generating nitrogen atoms reacting with the metal. Which species prevail in supplying nitrogen depends on nitriding conditions as well as the nature of the treated metal. Plasma nitriding of low-density powder metal (PM) products results in a formation of the layers whose thicknesses may depend on the gas pressure used for the process. Higher pressure can cause locally deeper penetration of the surface by active nitrogen species formed from ammonia compounds generated by the plasma. While a low processing pressure reduces this effect significantly. The formation mechanism of a locally thicker layer relies on the presence of open porosities in the surface as they can be penetrated by the ammonia species generated by the plasma. The same porosities cannot be penetrated by the ions of nitrogen formed at the same time since their mean free life is much shorter than that of ammonia species. ◼

Ultra-rapid synthesis of the MgCu2 and Mg2Cu Laves phases and their facile conversion to nanostructured copper with controllable porosity; an energy-efficient, reversible process

Porous copper nanoarchitectures are obtained selectively by acid-dealloying of Mg–Cu precursors prepared by microwave-induced-metal-plasma methods; the entire process is reversible.