Shock-induced structures in copper

Shock loading of M3 copper within strain rate range of 5·10 6-5,7·10 6 s -1 reveals a nucleation of structural objects of 5-30 µm in diameter, which present the three dimensional frameworks composed from shear bands of 50-200 nm spacing. The structures are shown to be nucleated by means of interference of longitudinal and periphery release waves. Transition of the material into structure unstable state responsible for the shear banding happens when rate of change of the velocity variance at the mesoscale becomes higher than the rate of change of the mean particle velocity. The sites of nucleation of 3D-structures are speculated to be the staking faults generated under action of chaotic velocity pulsations relevant to dynamic deformation. The physical model for formation of 3D-structures takes into account the intersection of the partial dislocations and Lomer - Cottrell barriers

Dynamic Strength of Submicrocrystalline Copper and Copper Alloys Obtained by High-Speed Pressing

The mechanical properties of copper with a purity of 99,8 wt. % and alloys Cu–0,03 wt. %Zr and Cu–0,1wt. %Cr with submicrocrystalline structure obtained by dynamic channel-angular pressing was studied. The tests were carried out under shock-wave compression with pressure up to 7 GPа and strain rate 10 5 s–1.Исследованы механические свойства меди чистотой 99,8 мас. % и сплавов Cu–0,03 мас. %Zr и Cu–0,1 мас. %Cr с субмикрокристаллической структурой, полученной методом динамического канально-углового прессования. Испытания проводились в условиях ударного сжатия с давлением до 7 ГПа и скоростью деформации 10 5 с–1.Работа выполнена в рамках государственного задания по теме «Структура» № АААА-А18-118020190116-6 и Программе Президиума РАН «Конденсированное вещество и плазма при высоких плотностях энергии»

Evolution of the Structure and Properties of the lowAlloyed Cu–Cr, Cu–Zr and Cu–Cr–Zr Alloys under High Strain Rate Deformation and Aging

The effect of high strain rate deformation by dynamic channel-angular pressing and subsequent annealing on structural changes, strength properties and electrical conductivity of dispersion-hardening alloys based on Cu–Zr, Cu–Cr and Cu–Cr–Zr systems was investigated.Исследовали влияние высокоскоростной деформации методом динамического канально-углового прессования и последующего отжига на структурные изменения, прочностные свойства и электропроводность дисперсионно-твердеющих сплавов Cu–Zr, Cu–Cr и Cu–Cr–Zr.Работа выполнена в рамках государственного задания по теме «Структура» № АААА-А18–118020190116–6 и проекта № 18–10–2-39 программы УрО РАН

STRUCTURE AND PROPERTIES OF COPPER AND ALLOYS UNDER EXTREME LOADING

The dynamic properties of technical copper and copper alloys with a submicrocrystalline (SMC) structure formed by the dynamic channel.angular pressing methodwere studied. The tests were carried out undershock.wave compressionwithintensity 6–7GPa·and speed deformation of (0.9–2.0)·10 5 s–1 . The effect of the dispersion and defects of SMC structure on its resistance to highspeed deformation and fractureto is estimated.Исследованы структура и динамические свойства технической меди и низколегированных сплавов на основе меди с субмикрокристаллической (СМК) структурой, полученной методом динамического канально.углового прессования. Испытания проводились в условиях ударного сжатия с давлением 6–7 ГПа и скоростью деформации (0,9–2,0)·10 5 с–1. Проведена оценка влияния дисперсности и дефектности СМК.структуры на ее сопротивление высокоскоростному деформированию и разрушению.Работа выполнена в рамках государственного задания по теме «Структура» № АААА-А18-118020190116-6 и при частичной поддержке УрО РАН (проект № 18-10-2-39)

Structural-Phase Transformations and Properties of Copper Alloys under High Strain-Rate Deformation

Исследованы структура и свойства дисперсионно-твердеющих сплавов на основе систем Cu–Zr и Cu–Cr–Zr при высокоскоростной деформации (~105 с-1) методом ДКУП и последующем отжиге (старении). Изучена роль легирования микродобавками хрома и циркония (0,03–0,20 мас. %), в достижении высокой твердости и термической стабильности СМК сплавов. Показано влияние ДКУП и старения на прочность и электропроводность сплавов.The structure and properties of dispersion-hardening alloys based on Cu–Zr and Cu–Cr–Zr systems under high strain-rate deformation (~10 5 с‑1) by the DCAP method and subsequent annealing (aging) are investigated. The role of alloying chromium and zirconium with microadditives (0,03–0,20 wt. %) in achieving high hardness and thermal stability of SMC alloys has been studied. The effect of DCAP and aging on the strength and electrical conductivity of alloys is shown.Исследование выполнено в рамках государственного задания Минобрнауки России по теме «Структура» № АААА-А18-118020190116-6 и при частичной поддержке РФФИ (проект № 20-43-660034).The study was carried out within the framework of the state assignment of the Ministry of Education and Science of Russia on the topic “Structure” No. AAAA18-118020190116-6 and with partial support of the RFBR (project No. 20-43-660034)

THE STRUCTURE OF SHELLS FROM COPPER M1 AND STEEL 20 COLLAPSED SHELLS UNDER THE ACTION OF SHOCK WAVES

Using the methods of metallography and electron microscopy, we studied the structure of shells made of steel 20 and copper grade M1, converging under the action of shock waves. It was found that the deformation behavior of the shells depends on the mass speed, the pressure in the shock wave, and the material properties of the shell itself. Three zones were found in collapsed samples: a spall zone, a central zone, and a deformation zone near a cylindrical surface.Методами металлографии, электронной микроскопии была исследована структура оболочек из стали 20 и меди марки М1, сошедшихся под действием ударных волн. Установлено, что деформационное поведение оболочек зависит от массовой скорости, величины давления в ударной волне и свойств материала самой оболочки. В схлопнутых образцах обнаружены три зоны: зона откола, центральная зона и зона деформации вблизи цилиндрической поверхности.Работа выполнена в рамках государственного задания по теме «Структура» № АААА-А18-118020190116-6 и при частичной поддержке УрО РАН (проект № 18-10-2-39)

DYNAMIC AND QUASI-STATIC MECHANICAL PROPERTIES OF IRON-NICKEL ALLOYS OF METEORITIC ORIGIN

In this work, the strength properties were determined during quasi-static and dynamic tests of four iron meteorites. Namely, tensile tests were carried out, as well as shock wave loading, in order to measure spall strength, Hugoniot elastic limit and dynamic yield strength.Исследование выполнено при финансовой поддержке Министерства науки и высшего РФ в рамках Программы развития УрФУ в соответствии с программой «Приоритет-2030»

Martensitic transformations in shape-memory Cu-Zn-AI alloys with the α\mathsf{\alpha}-phase particles and the bainite crystals

The martensitic transformations in Cu-Zn-A1 alloys undergoing the decomposition of $\beta$ solid solution with the formation of rod-like $\alpha$-phase or of plate-type bainite crystals have been studied by optical microscopy, electron microscopy and electron-probe microanalysis. The fine structure of the phases formed upon the partial decomposition of $\beta$-phase and upon the subsequent martensitic transformation was studied. The $\alpha {\to} \beta$ transformation was shown to occur in a crystallographically ordered manner and to obey the Kurdyumov-Sachs orientation relationships. The $\alpha {\to} \beta$ transformation includes features of both diffusional and martensitic transformations. The $\alpha$-phase formation inclues a crystals lattice reconstruction and the nucleation dislocations in periodically arranged slip planes. At the same time, the shape of the $\alpha$-phase crystals and their coalescence and changes in chemical composition are typical of diffusional transformation. The interactions of martensite crystals with particles of the $\alpha$ phase and bainite crystals were studied

Strain behaviour of shock waves loaded titanium nickelide during martensitic transformations

Plates of titanium nickelide (Ti-50.5 at. % Ni) rolled in the austenitic B2-state were loaded by shock waves with a pressures of 10 and 50 GPa. Dilatometry and X-ray diffraction show that the shock waves loading led to anisotropic martensitic transformations in the plates. The anisotropy of the transformations is caused by the directional motion of the plate substance in shock waves. The austenitic memory the samples had prior to the loading changed to the martensitic memory, inherent in the martensite deformation. The martensitic memory has not been retained after the reverse martensitic transformation; the samples had remembered the initial state with the austenitic memory. The carriers of the memory are particles of the precipitated phase (Ti$_3$Ni$_4$) and the dislocation structure formed upon rolling

Peculiarities of Thermoelastic Martensitic Transformation in the Cu-Zn-Al and Cu-Zn-Al-V after Decomposition of the β-Solid Solution

Dilatometric, metallographic, and electron-microscopic methods were used to study martensitic transformations in Cu-Zn-Al alloys that were subjected to a heat treatment to the decomposition of β solid solution at temperatures of α-phase precipitation (635-530°C) and bainite formation (300-125 °C). The partial decomposition and the accompanying redistribution of the components were shown to alter the type of martensitic transformation from nonthermoelastic to thermoelastic with a corresponding change in the martensite morphology from plate type to needle type (spear-shaped). A decrease in the temperature of isothermal anneal in the α+β range from 600 to 530°C substantially decrease the Ms temperature (by 140 °C). The temperature hysteresis of the transformation changes from 0 to 70 K