The microstructure and properties of the novel heat resistant Al–3Ce–7Cu alloy produced by selective laser melting were investigated. Fine Al
11
Ce
3
and Al
6.5
CeCu
6.5
eutectic phases were found in ...the microstructure. Annealing at temperatures in the 250–400 °C range leads to a decrease in the hardness. Hardness has larger values after annealing at 350 and 400 °C than at 250 °C due to the precipitation of nanosized particles. The low hardness after quenching and aging at 190 °C is caused by quench stress relief and the absence of aging hardening because of poor solid solution. The as-printed yield strength, ultimate tensile strength and elongation are 274 MPa, 456 MPa and 4.4%, respectively. High mechanical properties of the Al–3Ce–7Cu alloy were demonstrated by high temperature tension and compression tests.
A comparative study on the work hardening of Al–Mg and Al–Cu alloys was carried out using a Kocks–Mecking–Estrin type analysis of stress–strain curves obtained in tension tests at constant loading ...rate. As a result of the analysis, dependencies of forest dislocation storage and dynamic recovery rates on the Mg and Cu concentration have been derived. The work hardening behavior and the microstructure formation in the Al–Mg and Al–Cu alloys were shown to be similar despite the opposite effects of Cu and Mg on stacking fault energy as well as the differences in solute atom size and friction stress. The influence of alloying on the work hardening peculiarities and the dislocation substructure evolution was discussed in connection with the effects of solute–dislocation interaction.
Based on the results of compression tests in temperature ranges of 1100–1250°С and strain rates of 0.1–10 s
–1
, a rheological model of the deformation behavior of the 13CrMoNbV ferritic-martensitic ...steel is constructed. A fracture criterion for the 13CrMoNbV steel in the process of hot plastic deformation and a method for determining its critical value, based on tensile tests at a Gleeble 3800 complex for physical modeling of thermomechanical processes and the results of modeling using the finite element method,—are proposed. The rheological model and the fracture criterion showed satisfactory accuracy when calculating the deformation process under conditions of a complex stress–strain tension–torsion state at the Gleeble 3800 complex at a temperature of 1100°C.
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•The coefficient of thermal expansion of the AlSi11CuMn alloy manufactured by SLM is 19.1·10−6 °C−1.•The hardness of the as processed AlSi11CuMn alloy is 144HV.•The ultimate tensile ...strength of 354 MPa and elongation of 5.4% were obtained after heat treatment.
The microstructure and mechanical properties of the novel AlSi11CuMn alloy manufactured by selective laser melting were investigated in the as processed state and after heat treatment. A fine eutectic structure formed in the as processed alloy. A duplex size structure formed after solution treatment. The thermal expansion coefficient was 19.1·10−6 °C−1 in the 20–100 °C range which is typical for cast Al-Si alloys. Increasing annealing temperature from 190 to 275 °C leads to a sharp decrease in the alloy hardness from 136HV to 119HV after 2.5 h. The hardness was significantly reduced from 136HV to 79–82HV after solution treatment at 515 °C. The yield stress, ultimate tensile strength and elongation were 288 MPa, 354 MPa and 5.4%, respectively after solution treatment at 515 °C and aging at 180 °C for 8 h.
•Microalloying of Fe-19 Ga and Fe-27.4 Ga alloys by Tb (0.15–0.5 at%).•A significant improvement of the magnetostriction in Fe-19 Ga-0.37 Tb.•The magnetization, permeability, and magnetostriction ...improve with Tb.•The coercivity, remnant magnetization, and hysteresis losses decrease with Tb.•beyond Tb solubility, Tb-rich precipitates form and deteriorate the magnetic properties.
The current paper deals with the influence of Tb doping on magnetic and magnetostrictive properties of Fe-19 Ga-xTb (x up to 0.37 at%) and Fe-27.4 Ga-xTb (x up to 0.5 at%) alloys at room temperature by vibrating sample magnetometry and strain gauge methods. The magnetocrystalline anisotropy constant and the magnetic permeability are improved in Fe19 Ga-xTb alloys upon Tb addition. A significant enhancement of the magnetostriction up to ≈ 235 ppm in Fe-19 Ga-0.37 Tb alloys is observed.
Alloying of Fe-27.4 Ga with 0.3 at%Tb increases the magnetization, permeability, and magnetostriction, and decreases the coercivity, remanent magnetization, and hysteresis losses. Beyond this Tb content, a considerable amount of the phase enriched in Ga and Tb precipitates, which opposes magnetic domain wall motions and declines the magnetic properties.
An improvement of the magnetic properties in Fe-Ga-Tb alloys might be correlated to the magnetocrystalline anisotropy and the localized strain induced by Tb. The present work demonstrates that the full potential of Fe-Ga-Tb alloys is yet to be explored for engineering soft magnetic applications.
The microstructure and thermal and mechanical properties of (FeCoNiCuCr)
100−
x
-Nb
x
multiprincipal-element alloys have been investigated in the as-cast and heat-treated state. The alloys were ...smelted by arc-melting in argon atmosphere. As-cast samples were produced by copper mold casting. The structure was studied by scanning electron microscopy (SEM) and x-ray diffraction (XRD) analysis. The calculated phase diagrams of the Fe-Co-Ni-Cu-Cr-Nb system were used to predict the phase composition. The predicted thermodynamic temperatures and phase areas were compared with those obtained using differential scanning calorimetry (DSC) and the results of SEM observation, respectively. Addition of 10 at.% Nb caused phase separation of the alloy in the liquid state. Addition of Nb caused an increase in the yield strength by solid-solution hardening and by the formation of intermetallic compounds. Heat treatment also affected the mechanical properties of the studied alloys.
Composite materials based on alloys of the Al–Si–Mg system have been obtained via the introduction of 5, 10, and 15 wt % of SiC particles into the alloy melt and the solidification under a pressure. ...As a result of solidification under pressure, the porosity of the composite materials decreased substantially. An increase in the content of SiC particles in the composites enabled a smaller size of dendritic cells to be obtained. It has been shown by the X-ray diffraction method that, in the process of solidification under pressure, an interaction occurred between the matrix and reinforcing SiC particles. The presence of SiC particles in the structure of composites led to the acceleration of the aging process and to an increase in the peak hardness in comparison with the matrix alloy.
The effect of Zr addition to the novel Al-Er-Y alloy on microstructure, phase composition, recrystallization behavior, mechanical properties and electrical conductivity is studied. Formation of the ...Al3Y, Al3Er and Al3(Er,Y) intermetallic phases in the Al-Er-Y alloy is proved by SEM. Zirconium leads to the formation of the Al3(Er,Y,Zr) eutectic phase. We demonstrate the formation of nanosized Al3(Er,Y) and Al3(Er,Y,Zr) dispersoids in the Al-Er-Y and Al-Er-Y-Zr alloys, respectively. The recrystallization temperature for the Al-Er-Y alloy at about 365 °C is recorded by dynamic mechanical analyzer. Zirconium addition to the Al-Er-Y alloy increases the recrystallization temperature to above 400 °C. The YS and UTS of the Al-Er-Y alloy are decreased after annealing of the rolled sheets from 130 to 115 MPa and from 142 to 125 MPa, respectively. The average tensile properties of the Al-Er-Y-Zr alloy in the deformed and annealed conditions are YS = 144 ± 3 MPa and UTS = 156 ± 3 MPa with 11 ± 1% elongation. The Al-Er-Y alloy demonstrates a good electrical conductivity of 64–64.7% IACS. Zirconium addition decreases electrical conductivity to 57% IACS.
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•Al3Y, Al3Er and Al3(ErY) phases were formed in the AlErY alloy.•The formation of the 5 nm Al3(ErYZr) dispersoids in the AlErYZr alloy was showed.•Zr increased the recrystallization temperature of the AlErY alloy higher than 400 °C.•The YS = 144 MPa and UTS = 156 MPa with El. = 11% were found for the AlErYZr alloy.•The AlErY alloy demonstrated a good electrical conductivity in 64–64.7% IACS.
► The Ni50Pd30P20 bulk metallic glass produced by flux treatment and casing. ► Deformation behavior at room temperature. ► The serrated flow behavior appears to be chaotic. ► Serrated slow dynamics ...initially results from new shear bands. ► Later enlargement of shear bands takes place.
The Ni50Pd30P20 bulk metallic glass was produced by flux treatment and casing. The formation of a glassy structure of the studied alloy was confirmed by X-ray diffractometry and transmission electron microscopy. Its deformation behavior under uniaxial compression at room temperature was studied at the strain rate of 5×10−4s−1 as well as at three different strain rates at the quasistatic loading conditions. The serrated flow behavior appears to be chaotic and is analyzed with a stochastic model. The model suggests that the underlying serrated slow dynamics initially results from the appearance of new shear bands in the material, but as the experiment proceeds the nature of these dynamics change, and strain takes place by the enlargement of shear bands already present on the material.
