An Erratum to this paper has been published: https://doi.org/10.1134/S0031918X26600661
The structure, magnetic properties, and magnetic domains in rapidly quenched amorphous Co78.5Ni12.4Fe5.5Cr0.8Mn1.4Si1.1B3 ribbons were experimentally studied in as-quenched state and after treatment with argon ion flows generated in the vacuum chamber of an ion-plasma sputtering installation under specially selected conditions near the threshold for Ar ion energy at which sputtering of the surface of the ribbon samples occurs (approximately 1.3 keV). An explanation is proposed for the effectiveness of Ar ion treatment of the surface of rapidly quenched ribbon under the considered conditions. Obtained results can be useful for development magnetically soft layered composites for magnetic field sensors using magnetoimpedance and thermomagnetic effects.
In this paper, CoCrFeNiCuPrx (x = 0, 0.05, 0.1, 0.15, 0.2) high entropy alloy was prepared by mechanical alloying (MA)+ fast hot-pressing sintering (FHP), and the influence of Pr content on the microstructure and mechanical properties of the high entropy alloy was investigated. The results show that the CoCrFeNiCuPrx high entropy alloy powder is all composed of FCC structure. After adding Pr, the phase structure of the alloy bulk changes from Cr-poor FCC phase and Cr-rich BCC phase to Cr-poor and Ni-rich FCC phase, Cr-rich BCC phase, and hexagonal structure precipitation phase rich in Pr and Ni. With the increase of Pr content, the precipitated phase gradually aggregates and grows from dispersed fine particles into irregularly shaped masses. The compressive yield strength of the alloy first increases and then decreases with the increase of Pr content. The plastic strain gradually increases and the hardness gradually decreases. Both its yield strength and hardness are greater than those of the high-entropy alloy without Pr. The CoCrFeNiCuPr0.1 high entropy alloy exhibits outstanding comprehensive mechanical properties, with its compressive yield strength, compressive strength, plastic strain, and Vickers hardness reaching 1556.71, 1805.71, 21.16
The electrical resistivity and magnetization of Co2 – xMn1 + xAl (x = 0, 0.25, 0.5, 0.75, 1) Heusler alloys were experimentally studied. The electrical resistivity was measured in the temperature range from 4.2 to 300 K. The field dependences of magnetization were measured in fields up to 50 kOe at temperatures of 2 and 300 K. It was shown that the resistivity of the Co2MnAl alloy differs significantly from others both in magnitude and in the type of temperature dependence. The residual resistivity of the Co2MnAl alloy is the lowest and equal to 243 µΩ cm, while for the other alloys it is much higher: from 335 to 404 µΩ cm. The ρ(T) dependence for Co2MnAl shows a minimum at T = 35 K, then with temperature increasing a “metallic” growth is observed. For the Co1.75Mn1.25Al, Co1.5Mn1.5Al, Co1.25Mn1.75Al, and Mn2CoAl alloys, the resistivity decreases slightly with increasing temperature. The magnetization exhibits behavior characteristic of ferromagnets: it increases with the magnetic field and reaches saturation in fields above 10 kOe. It was found that with an x changing in the Co2 – xMn1 + xAl (x = 0, 0.25, 0.5, 0.75, 1) Heusler alloys kinks are observed in the concentration dependences of the resistivity and magnetization at x values between 0.25 and 0.5. This can be caused by changes in the electronic structure upon transition from the Co2MnAl topological semimetal to the Mn2CoAl spin gapless semiconductor.
This study explores the effect of varying Cr3C2 concentrations on the tribological properties of the deposited EWAC + Cr3C2 (20, 40, and 60 wt
Al–Zn–Mg–Cu alloys with trace addition of Ti element exhibit excellent mechanical properties and have been playing an indispensable role in the aerospace field. To further enhance the mechanical performance and promote broader engineering applications of these alloys, Al–8Zn–2Mg–1.6Cu–0.17Ti alloys with different Sc additions (x = 0, 0.1, 0.2, 0.3, and 0.4 wt
We report the results of a first-principles calculation of the structural, electronic, magnetic, mechanical, and dynamical properties of the full-Heusler alloys Rh2CoIn and the less explored Rh2CuIn. The main goal is to investigate to what extent these properties can be affected by Y-site substitution in Rh2YIn (Y = Co and Cu). Structural optimization confirms that both compounds crystallize in the highly stable Cu2MnAl-type (L21) phase. Electronic band structure and density of states reveal that Rh2CoIn and Rh2CuIn exhibit metallic character. However, the two systems have distinct magnetic behavior: while Rh2CoIn is ferromagnetic due to the partially filled d orbitals of Co and Rh atoms, the fully filled d shell of Cu renders Rh2CuIn, that is, non-magnetic. The total magnetic moment of Rh2CoIn is found to be 2.969 μ_B , which violates the Slater–Pauling rule. This rule remains not satisfied under the influence of hydrostatic pressure and temperature. Elastic constants calculations indicate that both alloys are mechanically stable and ductile, with Rh2CoIn showing higher stiffness and thermal stability. It is shown that substituting Co with Cu slightly softens the crystal lattice and enhances elastic anisotropy. From phonon dispersion curves, we demonstrate the dynamical stability for the two alloys.
The homogenization treatment is essential for TiB2/6082Al composite to eliminate elements segregation and coarse nonequilibrium phases, however, the microstructure evolution and modification mechanisms of TiB2 during homogenization process remain insufficiently understood. In present work, the homogenization process of TiB2/6082Al composite was optimized systematically, and the microstructure evolution during the casting and homogenization was thoroughly clarified. The microstructure of as-cast TiB2/6082Al is composed of fine equiaxed grains with average size of 64.5 μm and coarse nonequilibrium phase. With the homogenization temperature increases from 540 to 560°C, the fraction of continuous Al(Fe,Mn)Si phase decreases significantly, while overburning occurs with the temperature further increases to 570 and 580°C. During the homogenization under optimal process (560°C/10 h), the coarse Al(Fe,Mn)Si and Al3Ti dissolved into matrix through the diffusion process driven by concentration gradient, and promotes the homogenization of component and microstructure.
The irreversibility field Hirr is a parameter that defines the boundary between hysteretic and reversible behavior in the magnetic properties of type-II superconductors. Unlike the upper critical field Hc2, at which the material completely experiences transition to the normal state, Hirr(T) marks the practice-related application limit of a superconductor. For technologically relevant materials, such as MgB2 and high-temperature superconductors (HTSs), the difference between Hc2 and Hirr can be substantial, making the problem of the irreversibility field one of the central issues in applied superconductivity. The Hirr phenomenon is believed to have been first discovered at the HTS; however, subsequent research has demonstrated its universality for all type-II superconductors, including classical low-temperature materials such as Nb, Nb–Ti, and Nb3Sn. It is noted that similar effects in earlier works were explained within the scope of the third critical field Hc3. This observation, although requiring further verification, prompts a re-evaluation of historically established definitions of critical fields. The paper reviews experimental methods for determining Hirr, including magnetometry, low-frequency susceptibility measurements, resistive curve registration, and extrapolation of the field dependence of the volume pinning force. The limitations of each method are emphasized, which allows avoiding erroneous interpretations. Particular attention is given to the methodology of two-dimensional current–voltage characteristics (2D I–V), which, unlike the aforementioned approaches, allows for an unambiguous detection of the presence or absence of quantized magnetic flux through the orthogonality of the electric field E and magnetic induction B vectors. The paper traces the evolution of theoretical concepts regarding the irreversibility field. Traditionally, Hirr has been associated with the loss of vortex pinning efficiency and the transition to a dissipative vortex liquid. However, contemporary experimental data obtained by the 2D I–V method challenge this paradigm. Specifically, for Nb–Ti tapes, it has been shown that the structure of quantized magnetic flux above the value of Hirr disappears, and the observed effects are explained by macroscopic inhomogeneity of superconducting properties. A return to the historically first concept, where structural inhomogeneity is considered the defining factor for irreversibility, opens new perspectives for comprehension of the nature of Hirr. The obtained results indicate the limitations of the vortex pattern in explaining the transition to reversible behavior and emphasize the need of rethinking the role of macroscopic inhomogeneity in forming the current-carrying properties of practical superconductors.
The solidification microstructures of the Zn–5.4Al–0.6Ti-modified Zn–2.7Mg–2.5Al alloy and its mechanical properties, before and after modification, were analyzed. The results revealed that the Zn–5.4Al–0.6Ti alloy comprised η-Zn phase, binary Zn–Al eutectic, ternary T phase, and Al3Ti phase, and its melting temperature ranged from 383.8 to 391.5°C. As the Zn–5.4Al–0.6Ti content increased, the area fraction of the primary η-Zn phase in the Zn–2.7Mg–2.5Al alloy initially decreased and then increased. The tensile strength, impact toughness, and Vickers hardness of the alloy initially increased and then decreased with the increasing modifier content, while the elongation continuously decreased. At a modifier content of 7 wt
Double compression tests were performed on six vanadium microalloyed steels with various vanadium and nitrogen contents by using a Gleeble 3800 thermal mechanical simulator to study the static recrystallization behaviors of the tested steels. With the assistance of the experimental data, static recrystallization softening curves were determined, the values of activation energy were obtained and the kinetics models were constructed. The effect of vanadium and nitrogen contents on the static recrystallization behavior of vanadium microalloyed steel was analyzed. The results show that vanadium and nitrogen play a different role in the static recrystallization behaviors of vanadium microalloyed steel. In the absence of nitrogen, the static recrystallization softening curve exhibits a typical sigmoidal shape. However, with the addition of a certain amount of nitrogen, the softening curves display distinct plateau characteristics. The position and duration of these plateaus are closely related to the vanadium and nitrogen contents. Therefore, establishing an accurate kinetic model for vanadium-microalloyed steels must account for the content of these microalloying elements.Increasing solely the vanadium content in the steel leads to a notable rise in the activation energy for static recrystallization. The effect of nitrogen content on the activation energy, however, primarily depends on the inhibitory effect of carbonitride precipitation on static recrystallization. As the nitrogen content increases, the increment in activation energy for static recrystallization becomes more pronounced.
The thermomagnetic characteristics of vanadium-alloyed Ni–Mn–In Heusler alloys are investigated in this work. With increasing vanadium concentration, the characteristic temperatures of the metamagnetostructural phase transition shift towards the low-temperature region. The critical magnetic field required to induce a complete metamagnetostructural phase transition, calculated based on the temperature hysteresis and on the temperature range of transition existence, exhibits a significant discrepancy. The temperature dependences of the change in magnetization and the latent heat of the phase transition are constructed using the Clausius–Clapeyron equation. A comparison is provided for the derivatives of magnetization with respect to entropy and of the characteristic temperature with respect to the magnetic field, which are terms of the equation. The magnetocaloric effect was measured by a direct method in magnetic fields up to 1.8 T.
Iron is one of the main elements affecting MnTe inclusion in steel, in order to explore the most possible atomic structure of (Mn,Fe)Te, this work built MnTe supercell and (Mn,Fe)Te structures by first-principle method, the atomic ratios of Mn and Fe (NMn : NFe) in atomic structures are 15 : 1, 7 : 1 and 3 : 1, respectively. The s and p orbitals of Fe lose more electrons than that of Mn, the ion interaction potential between Fe and Te is stronger than that between Mn and Te. At [001] direction of (Mn,Fe)Te, the covalent bonds, Fe–Mn and Mn–Mn form, and the covalent charge between Fe–Mn is provided by Fe. The formation energy of the solid solution structure with NMn : NFe = 7 : 1 is the largest, 0.90 eV, it means that structure is the most stable. With increase of Fe atoms in solid solution, the bulk modulus, shear modulus and Young’s modulus of the solid solution first decrease and then increase. The atomic ratio of manganese to iron in telluride is confirmed (approximately 7 : 1) by electron probe micro-analyzer (EPMA) experiment for Te-containing steel.
The relationship between the microstructure and mechanical properties of DP980 high-strength low-alloy steel (DP980 steel) and QP980 high-strength low-alloy steel (QP980 steel) after roll forming is studied. In the experiments, forming angles of 10°, 20°, and 30° are investigated for 1, 2, and 3 forming passes. The springback angle and microhardness of the bending parts of the DP980 and QP980 steels are tested, and the tensile strength and elastic modulus are obtained. Optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) are used to analyze the microstructures of the bending parts. The results show that with an increase in the design forming angle, the martensite content, plastic deformation obstacles, yield strength, tensile strength, elastic strain, and springback increase gradually. The effect of an increase in the forming angle on the microhardness is not obvious. In the multi-pass forming experiment, the springback angle of the DP980 steel increases with an increase in the number of designed forming passes. In the single-pass roll-forming experiment on QP980 steel, with an increase in the design forming angle, the springback angle initially increases and then decreases, the size of the martensite decreases, the number of strip martensites increases, and preferential transformation of residual austenite on the outer and inner edges occurs. When the design forming angle is 20°, the martensite inside the bending part exhibits an uneven distribution. The inner and outer strains are not uniform, the microhardness increases with the increasing forming angle, and the work-hardening phenomenon is evident. In the multi-pass forming experiment, the springback angle increases with an increase in the number of passes. The microhardness of the DP980 and QP980 steels decreases with an increase in the number of passes, and a softening phenomenon appears, which is caused by the process characteristics of roll forming.
This research presents a systematic investigation into the effects of varying heat treatment temperatures and holding durations on the microstructure, mechanical properties, and fracture behavior of Ti6Al7Nb plates. The results demonstrate that heat treatment effectively modulates grain size, morphology, and crystallographic orientation distribution, thereby influencing material anisotropy and mechanical response. Tensile properties exhibit pronounced anisotropic behavior: longitudinal strength values are lower than transverse counterparts, with the transverse yield strength exceeding that in the longitudinal direction. Optimal microstructural characteristics and balanced mechanical properties are achieved through annealing near the beta transition temperature. Thus, the rational design and control of heat treatment protocols are critical for attaining an optimal combination of strength and toughness in Ti6Al7Nb alloy.
This study presents a comparative investigation of the microstructure and mechanical properties of a low-alloy medium-carbon steel (0.33C–1.85Si) processed via conventional quenching and tempering (Q T) and a quenching and partitioning (Q P) route. The Q P treatment was designed to achieve an optimal strength-ductility balance through the targeted stabilization of film-like retained austenite. It comprised interrupted quenching at 220°C followed by isothermal partitioning at 400°C for 60 s. Microstructural characterization using X-ray diffraction, scanning electron microscopy, and electron backscatter diffraction revealed that the Q P treatment produces a complex multiphase structure. This structure consists of 88.0
This study examines the strength and plasticity behavior of shaftless, transversely isotropic rotating disks operating under combined centrifugal loading and radial thermal gradients. The governing field equations are formulated in cylindrical coordinates for axisymmetric steady-state conditions. Nonlinear elastic and elastic–plastic transitions are modeled using Seth’s transition theory to capture the progression of material yielding induced by thermo-mechanical effects. Numerical simulations are carried out to predict radial displacement fields, stress distributions, and the development of plastic zones in the disk domain. Validation is achieved by reducing the formulation to isotropic and homogeneous configurations, demonstrating close agreement with benchmark results available in the literature. Parametric analyses using representative transversely isotropic materials such as beryl, compared against isotropic copper, reveal that the anisotropy and radial density variations significantly mitigate peak stresses and postpone plastic initiation. These findings underscore the advantages of transversely isotropic configurations in enhancing strength, thermal resistance, and structural reliability of high-speed rotating components including flywheels, rotors, and thermo-mechanical coupling systems.
This paper presents a first-principles analysis of the structural, electrical, optical, and thermodynamic characteristics of cubic KInCl3 perovskite by density functional theory (DFT). The structural optimization verifies the mechanical stability of the system, indicating a marginally compressed lattice and a comparatively low bulk modulus of 22 GPa. The electronic band structure reveals a direction-dependent band gap, varying from a low 0.15 eV to a broad 5.40 eV gap, highlighting possibilities for ultraviolet (UV) optoelectronic applications. The density of states (DOS) study reveals substantial contributions from Cl-p and In-d orbitals in the valence band (VB), as well as from K-d and In-p orbitals in the conduction band (CB). The optical investigations of the structure demonstrate significant absorption in the ultraviolet spectrum, a static dielectric constant of 3.02, a maximum refractive index of 2.15, and a peak absorption coefficient of 1.17 × 108 m–1. The thermodynamic evaluations at different temperatures and pressures exhibit characteristic behavior in thermal expansion, entropy, heat capacity, and Debye temperature, thereby affirming thermal and mechanical stability. The results indicate that KInCl3 is a viable choice for high-energy optoelectronic, thermomechanical, and UV filtering applications.
In this study, Stellite-6 was deposited onto 316L steel using the laser cladding process. The defect-free 500 μm thickness of Stellite-6 coating was achieved on the steel substrate. The X-ray diffraction revealed the presence of chromium carbide along with a cobalt-rich region in the Stellite-6 cladding region. Throughout the laser-processed region, the orientation of the nanoscale lamellar carbide (Cr7C3) exhibited notable variability, which is pivotal to its mechanical properties. A nanohardness test at 50 points with a load of 7500 μN showed values ranging from 6.77 to 9.64 GPa within the lamellar carbide (Cr7C3) region, reflecting the differences in lamellar structure orientation. Similar studies were carried out on the nanowear surface, maintained under the same load conditions. The geometry of the indenter is Berkovich. The speed and number of cycles were 0.277 and 3 μm/s, respectively. The number of data points collected in the test to draw the wear depth curve was 27.600. It revealed that the non-parallel orientations of the lamellar carbide (Cr7C3) not only displayed higher nanohardness but also resulted in reduced wear depth, compared to regions with parallel orientation. In the non-parallel orientations, the force transferred from one lamellar strip to the next was reduced by the sin(θ) value since sin(θ) is less than 1 for angles between 0° and 90°. As a result, the force transferred to the last lamellar carbide (Cr7C3) strip was significantly lower. Therefore, the force at the last lamellar carbide (Cr7C3) strip in the non-parallel orientations were less than that in the parallel orientation. Intriguing phenomena were observed in the simulated annealing surface, including lattice formations, material pile-up, and domain structures in both the nanohardness and nanowear track regions. Notable contrasts were identified between cobalt-rich areas and lamellar carbide.
This study explores the influence of different explosive thicknesses, te (38 and 47 mm) and standoff distances, SOD (5 and 10 mm), on the interface macrostructure and Vickers micro-hardness of commercially pure1050 aluminum and zinc explosive welding. At lower explosive thickness combined with a minimal standoff distance, the weld interface exhibited a predominantly straight morphology, indicating limited plastic deformation and interfacial instability. In contrast, joints fabricated using a higher explosive thickness (47 mm) developed a characteristic wavy interface, largely independent of the standoff distance, reflecting enhanced collision velocity and jetting behavior. Under conditions of higher explosive thickness and increased standoff distance, a continuous molten interfacial layer was observed, consisting of Al–Zn intermetallic compounds such as AlZn and Al2Zn3, as confirmed by energy dispersive X-ray analysis (EDAX) and X-ray diffraction (XRD). Vickers micro-hardness measurements revealed a pronounced increase in hardness with increasing explosive thickness, with peak hardness values recorded in the vicinity of the weld interface (20 μm) due to severe plastic deformation. Furthermore, all experimental welding conditions were found to be placed within the successful regimes of the weldability window, an analytical estimation, enabling reliable prediction of interface morphology.
