Design and development of Ti-Ni, Ni-Mn-Ga and Cu-Al-Ni-based alloys with high and low temperature shape memory effects

In recent years, multicomponent alloys with shape memory effects (SMEs), based on the ordered intermetallic compounds B2-TiNi, L21-Ni2MnGa, B2- and D03-Cu-Me (Me = Al, Ni, Zn), which represent a special important class of intelligent materials, have been of great interest. However, only a small number of known alloys with SMEs were found to have thermoelastic martensitic transformations (TMTs) at high temperatures. It is also found that most of the materials with TMTs and related SMEs do not have the necessary ductility and this is currently one of the main restrictions of their wide practical application. The aim of the present work is to design and develop multicomponent alloys with TMTs together with ways to improve their strength and ductile properties, using doping and advanced methods of thermal and thermomechanical treatments. The structure, phase composition, and TMTs were investigated by transmission- and scanning electron microscopy, as well as by neutron-, electron- and X-ray diffraction. Temperature measurements of the electrical resistance, magnetic susceptibility, as well as tests of the tensile mechanical properties and special characteristics of SMEs were also used. Temperature-concentration dependences for TMTs in the binary and ternary alloys of a number of quasi-binary systems were determined and discussed. It is shown that the ductility and strength of alloys required for the realization of SMEs can be achieved through optimal alloying, which excludes decomposition in the temperature range of SMEs' usage, as well as via various treatments that ensure the formation of their fine- (FG) and ultra-fine-grained (UFG) structure. © 2019 by the authors.Funding: This work was performed within the framework of state task “Structure”, grant no. AAAA-A18-118020190116-6 and the cooperative laboratory of the Ural Federal University n.a. the First President of Russia B.N. Yeltsin and the Mikheev Institute of Metal Physics of the Ural Branch of the Russian Academy of Sciences

Crystal growth and preliminary X-ray study of glutamic acid specific serine protease from Bacillus intermedius

The glutamic acid specific protease (glutamyl-endopeptidase) from Bacillus intermedius, strain 3-19, was isolated and purified using ion exchange chromatography on CM-cellulose and Mono-S FPLC column. The conditions for crystallization of the enzyme have been discussed. The crystals of enzyme were grown using hanging-drop vapor-diffusion technique. Crystals belong to the space group C2 with unit cell parameters of a = 61.62 Å, b = 55.84 Å, c = 60.40 Å, β = 117.6° X-ray diffraction data to 1.68 Å resolution were collected using synchrotron radiation (EMBL, Hamburg) and an imaging plate scanner. © 1999 Elsevier Science B.V. All rights reserved

The Effect of Heat Treatment on the Structure and Mechanical Properties of Nanocrystalline Cu–14Al–3Ni Alloy Subjected to High-Pressure Torsion

Abstract: The effect of heat treatment on the microstructure, phase composition, mechanical properties, and microhardness of the shape-memory Сu–14 wt % Al–3 wt % Ni alloy prepared in the nanocrystalline state, which results from the severe plastic high-pressure torsion (HPT), is studied. Electron microscopy and X-ray diffraction analysis are used in combination with electrical resistivity measurements in order to obtain data on the peculiarities of thermoelastic martensitic transformations and decomposition in the HPT-processed alloy subjected to thermal actions. © 2021, The Author(s).The study was performed in terms of state assignment no. АААА-А18-118020190116-6 (Struktura) of the joint laboratory of the Institute of Metal Physics, Ural Branch, Russian Academy of Sciences and Ural Federal University

Multicomponent alloys with thermally, mechanically and magnetically controlled shape memory effects

This paper presents a brief review of the systematic study of the influence of the chemical composition on the structure, phase transformations and physical properties of binary and quasi-binary Ti-Ni, TiNi-TiFe, TiNi-NiCu, NiMn-NiGa and Ni2MnGa-Ni3Ga systems, which undergo thermoelastic martensitic transformations (TMT) and related with them thermally, mechanically, or magnetically controlled shape memory effects (SME). The effect of alloying with a third component on the behavior of critical temperatures and the TMT sequence has been established, and their generalized diagrams have been constructed. It is shown that the morphology of thermoelastic martensite is a hierarchy of packets of thin coherent crystals. © Published under licence by IOP Publishing Ltd.Russian Foundation for Basic Research, RFBR: 18-32-00529 mol_аUral Branch, Russian Academy of Sciences, UB RAS: 18-10-2-39Federal Agency for Scientific Organizations: АААА-А18-118020190116-6This work was performed within the state task of Federal Agency for Scientific Organizations (theme Struktura, no. АААА-А18-118020190116-6), with the support of the Project UB RAS (no. 18-10-2-39) and was partly supported by the Russian Foundation for Basic Research (project no. 18-32-00529 mol_а)

Glutamyl endopeptidase of Bacillus intermedius strain 3-19. Purification, properties, and crystallization

A homogeneous glutamyl endopeptidase splitting peptide bonds of glutamic and, rarely, of aspartic acid residues in peptides and proteins was isolated from Bacillus intermedius 3-19 culture filtrate using chromatography on CM-cellulose and Mono S. The enzyme molecular mass is 29 kD and the p/ is 8.4. The proteinase is inhibited by DFP. The enzyme, like other glutamyl endopeptidases, reveals two pH optima (pH 7.5 and 9.0) for casein and one (pH 8.0) for Z-Glu-pNA hydrolysis. The Km for the hydrolysis of the latter substrate is 6 mM. The enzyme activity is optimal at 55°C. The enzyme is stable in the pH range 6.5-11.0. Its N-terminal sequence shows 56% coinciding residues when compared with that of Bacillus licheniformis glutamyl endopeptidase. Crystal prisms or plates 0.25-0.3 × 0.15 × 0.07-0.1 mm have been grown using the vapor diffusion technique in a hanging drop followed by macroseeding. The crystals belong to the space group B2 with the following unit cell parameters: a = 69.59 Å; b = 61.61 Å; c = 56.11 Å; γ = 117.57°. The X-ray data set to 1.7 Å resolution has been collected on an automatic synchrotron (EMBL Hamburg Station)

Structure and Phase Transformations of Ni-Mn-Fe Based Alloys

The structure and martensitic transformations of the alloys, based on the systems Ni50Mn50-хFex (x = 0–25 at. %) и Ni50-yMn50Fey (y = 0–25 at. %), were investigated by X-ray diffraction and electron microscopy. The peculiarities of structure and phase composition were investigated from the chemical composition of alloys.Методами дифракции рентгеновских лучей и электронной микроскопии исследованы структура и мартенситные превращения сплавов систем Ni50Mn50-хFex (x = 0–25 ат. %) и Ni50-yMn50Fey (y = 0–25 ат. %). становлены особенности структуры и фазовый состав сплавов в зависимости от их химического состава.Работа выполнена в рамках государственного задания МИНОБРНАУКИ России (тема «Структура», № АААА-А18-118020190098-5) при частичной поддержке РФФИ (проект № 18-32-00529 мол_а)

Multicomponent and High-Entropy Alloys: Definitions, Synthesis Methods, Structure and Properties

Представлен обзор многокомпонентных металлических сплавов (принципов их легирования, условий синтеза, структуры, фазового состава, физико-механических свойств). Рассмотрены особенности легирования и фазовых превращений в алюминиевых сплавах, полифункциональных низкомодульных медных и титановых сплавах и интерметаллидах, интерметаллических соединениях на основе никеля (фаз Гейслера).A review of multicomponent metal alloys (principles of their alloying, synthesis conditions, structure, phase composition, physical and mechanical properties) is presented. The features of alloying and phase transformations in aluminum alloys, multifunctional low-modulus copper and titanium alloys and intermetallides, intermetallic compounds based on nickel (Geisler phases) are considered

STUDY OF PHASE TRANSFORMATIONS OF THE MICROSTRUCTURE OF ALLOYS BASED ON BINARY ALLOY OF STOICHIOMETRIC COMPOSITION Ni-Mn

Микроструктуру сплава номинального состава Ni50Mn50 изучали методами микроскопии видимого света (ОМ), сканирующей (СЭМ) и просвечивающей электронной микроскопии (ПЭМ). Анализ изображений выполнен в среде программного обеспечения SIAMS 800 и нейросети SIAMS AIM. Изучена микроструктура сплава в мартенситном состоянии и после естественного старения. Фазовый состав и параметры кристаллических решеток фаз устанавливали методом рентгеноструктурного фазового анализа (РФСА) и дифракции обратно рассеянных электронов (EBSD).The microstructure of the alloy with the nominal composition Ni50Mn50 was studied by visible light microscopy, scanning microscopy, and transmission electron microscopy. Image analysis was performed in the SIAMS 800 software environment and the SIAMS AIM neural network. The microstructure of the alloy in the martensitic state and after natural aging was studied. The phase composition and crystal lattice parameters of the phases were determined by X-ray diffraction phase analysis and electron backscatter diffraction.Работа выполнена в рамках государственного задания МИНОБРНАУКИ России (Шифр «Структура» Г.р. № 122021000033-2). Работа выполнена с использованием оборудования ЦКП «Испытательный центр нанотехнологий и перспективных материалов» ИФМ УрО РАН. При финансовой, технической и программной поддержке ООО «СИАМС»

Crystal growth and preliminary X-ray study of glutamic acid specific serine protease from Bacillus intermedius

The glutamic acid specific protease (glutamyl-endopeptidase) from Bacillus intermedius, strain 3-19, was isolated and purified using ion exchange chromatography on CM-cellulose and Mono-S FPLC column. The conditions for crystallization of the enzyme have been discussed. The crystals of enzyme were grown using hanging-drop vapor-diffusion technique. Crystals belong to the space group C2 with unit cell parameters of a = 61.62 Å, b = 55.84 Å, c = 60.40 Å, β = 117.6° X-ray diffraction data to 1.68 Å resolution were collected using synchrotron radiation (EMBL, Hamburg) and an imaging plate scanner. © 1999 Elsevier Science B.V. All rights reserved