Effect of Mn and V on structure and mechanical properties of high-entropy alloys based on CoCrFeNi system

Microstructure and mechanical properties of equimolar composition alloys FeCrCoNi, FeCrCoNiV, FeCrCoNiMn and FeCrCoNiMnV were studied in as-solidified and annealed conditions. The FeCrCoNi and FeCrCoNiMn alloys were single-phase FCC solid-solutions in both conditions. However, the FeCrCo- NiV and FeCrCoNiMnV alloys consisted of the intermetallic r-phase matrix with a tetragonal crystal lattice and precipitates of a disordered FCC phase. The crystal structures of these alloys were found to be not affected by annealin

Structure and high temperature mechanical properties of novel nonequiatomic Fe-(Co, Mn)-Cr-Ni-Al-(Ti) high entropy alloys

Four non-equiatomic Fe-(Co, Mn)-Cr-Ni-Al-(Ti) high entropy alloys, namely Fe₃₆Mn₂₁Cr₁₈Ni₁₅Al₁₀, Fe₃₆Co₂₁Cr₁₈Ni₁₅Al₁₀, Fe₃₅Mn₂₀Cr₁₇Ni₁₂Al₁₂Ti₄, and Fe₃₅Co₂₀Cr₁₇Ni₁₂Al₁₂Ti₄ alloys, were produced by arc melting. Structures and compression mechanical properties of the as-cast alloys were examine

Structure and mechanical properties of B2 ordered refractory AlNbTiVZrx (x=0-1.5) high-entropy alloys

Structure and mechanical properties of the AlNbTiVZrx (x=0; 0.1; 0.25; 0.5; 1; 1.5) refractory high-entropy alloys were investigated after arc melting and annealing at 1200°C for 24 h. The AlNbTiV alloy had a B2 ordered single phase structure. Alloying with Zr resulted in (i) change of the degree of order of the B2 phase; and (ii) precipitation of the Zr5Al3 and C14 Laves ZrAlV phase

Aging behavior of the HfNbTaTiZr high entropy alloy

The HfNbTaTiZr high entropy alloy was produced by vacuum arc melting, homogenized at 1200 C, and annealed at 600-1000 C for 1-100 h. Structure and microhardness of the annealed alloy were investigated. A strong increase of microhardness after aging treatment at 600 C was found. Formation of second hcp phase particles in the bcc matrix after annealing at 600 and 800 C was also revealed. Effect of precipitation of second phase particles on microhardness was analyze

Effect of Al on structure and mechanical properties of Fe-Mn-Cr-Ni-Al non-equiatomic high entropy alloys with high Fe content

Microstructure and mechanical properties of the Fe-Mn-Cr-Ni-Al system non-equiatomic high entropy alloys with a different Al content (x =0-14 at.%) were studied in the present wor

Novel high-entropy materials and ways of their nanostructurization

A new class of metallic materials, so-called “high-entropy alloys” (HEAs), was under review. Various definitions of these alloys are given, their main differences from the conventional alloys are indicated. The dynamics of publications in recent years in variousdatabases indicates that there is an inexhaustible interest in these alloys. The unique set ofproperties makes these alloys suitable for any application (low temperature applications, aerosphere, nuclear power etc.

Phase evolution of the AlxNbTiVZr (x = 0; 0.5; 1; 1.5) high entropy alloys

AlxNbTiVZr (x = 0; 0.5; 1; 1.5) high entropy alloys were fabricated by vacuum arc melting and annealed at 1200 °C for 24 h. The NbTiVZr alloy had single body centered cubic (bcc) solid solution phase after annealing at 1200 °C, while, in the Al-containing alloys, C14 Laves and Zr2Al-type phases are found. The alloys were subjected to annealing at 800 °C and 1000 °C. It was shown that annealing temperature (800 °C or 1000 °C) weakly affected the produced phases but the Al content had pronounced effect on structure of the annealed alloy

Structure and mechanical properties of the refractory multicomponent alloys of the Ta-Ti-V-Zr-Al system

Refractory high-entropy alloys of the Ta-Ti-V-Zr-Al system, in which the V and Ta contents were varied, were investigated. Criteria, based on the thermodynamic parameters of the binary alloys, melting temperatures of the components, geometric and electronic characteristics of atoms, were used to calculate the possible phase-structural state of the alloys; results were compared with experimental data. Microstructural studies showed the presence of a typical dendritic structure in as-cast alloys with an average grain size of 40 μm, which depends on the concentration of the constituent elements. The microhardness of the alloys was theoretically calculated and experimentally investigated. It was found that the microhardness calculation, based on the data of the valence electrons concentration, bulk modulus and shear modulus, allows to estimate satisfactorily the value of microhardness.Було досліджено тугоплавкі високоентропійні сплави системи Ta-Ti-V-Zr-Al, в якій варіювався вміст V та Ta. Було запропоновано критерії на основі термодинамічних параметрів для бінарних сплавів, температур плавлення компонентів, геометричних та електронних характеристик атомів компонентів для розрахунку можливого фазово-структурного стану сплавів та проведено порівняння із експериментальними даними. Дослідження мікроструктури показали наявність типової дендритної структури в литих сплавах з середнім розміром зерна на рівні 40 мкм, що залежить від концентрації складових елементів. Теоретично розраховану мікротвердість сплавів підтверджено експериментально. Виявилось, що розрахунок мікротвердості на основі концентрації валентних електронів, а також її залежності від об’ємного модуля та модуля зсуву дозволяє зрозуміти порядок величин мікротвердості.Были исследованы тугоплавкие высокоэнтропийные сплавы системы Ta-Ti-V-Zr-Al, в которой варьировалось содержание V и Ta. Предложены критерии на основе термодинамических параметров для бинарных сплавов, температур плавления компонентов, геометрических и электронных характеристик атомов компонентов для расчета возможного фазово-структурного состояния сплавов и сравнения с экспериментальными данными. Исследования микроструктуры показали наличие типичной дендритной структуры в литых сплавах со средним размером зерна на уровне 40 мкм, что зависит от концентрации составляющих элементов. Теоретически рассчитанная микротвердость сплавов была экспериментально подтверждена. Оказалось, что расчет микротвердости на основе концентрации валентных электронов, а также ее зависимости от объемного модуля и сдвига модуля позволяет понять порядок величин микротвердости