The work hardening behavior of dual-phase Mg–8Li–3Al–1Nd alloy sheet is investigated at 293–473 K with a strain rate of 0.083–0.00083 s−1. Experiment results show that the flow stress is sensitive to deformation conditions, and decreased with the increased of temperature and the reduced of strain rate. On the basis of flow stress curves, the work hardening behavior is analyzed as work hardening rate (θ) with net flow stress (σ-σy) and true strain (εp) curves, which is defined as four stages: stage II (linear hardening stage), stage III and IV (softening stage), stage V (late deformation stage), but the work hardening stage II only occurs under certain conditions. The stage II, III and IV can be expressed by three models. By the models, the work hardening rate can be predicated.

The microstructures and magnetic properties of Co28Fe28Ni19Si13B12 high-entropy amorphous toroidal cores are investigated by X-ray diffractometer (XRD), transmission electron microscopy (TEM), MATS -2010 SD/MATS2010SA soft magnetic DC (AC) tester, WK6500B LCR bridge and precision LCZ tester. The results indicate that the alloy combines high curie temperature (Tc) and excellent soft magnetic properties. After heat treatment, the Co7Fe3 phase first precipitates in the alloy, and then follows the lamellar precipitate as Fe -B and Ni -Si phase. At elevated temperatures, the Co7Fe3 phase is transformed into the (Ni, Fe) phase with a precipitation of the Co2B phase. Compared to normal annealing (NA), the ordered rearrangement of domains induced by the magnetic field during heat treatment simplifies the domain structure and significantly improves the magnetic properties. Following stepwise longitudinal magnetic field annealing (NA+LFA), rectangular hysteresis loops are formed through domain movement, enhancing saturation induction (Bs) and remanence ratio, while reducing coercivity (Hc) and permeability. Conducting stepwise transverse magnetic field annealing (NA+TFA) increases permeability, maintains constant magnetic conductivity, reduces losses, and the ability to resist external direct current (DC) field interference is greatly enhanced.

The crystallized behavior, microstructure and magnetic properties of Co 28 Fe 28 Ni 19 Si 13 B 8 Cu 1 Nb 1 Mo 2 highentropy metallic glass are studied by DSC, XRD, TEM and VSM. The results show that two crystallization peaks occur with a difference of approximately 129 - 149 K, but the activation energy is different. The activation energy of the first peak is 175.3 kJ/mol and the second is that of 460.1 kJ/mol. After annealing, the Co 7 Fe 3 phase first precipitates with a feature of three-dimensional growth. When the annealing temperature is higher than the second crystallization temperature, the phases such as (Fe,Ni,Mo) 23 B 6 , Co 3 Mo 2 Si, Co 4 B, Fe 3 Mo precipitate sequentially, meanwhile Cu accumulates into small clusters to provide heterogeneous nucleation centers for the crystalline phase in the early stage of crystallization. Finally, the Hc increase with temperature, and the Ms first increasing and then decreasing with the maximum value of 93.11 emu/g at 893 K.

本文研究了Fe21.43Co21.43Ni21.43Mn5.36Al5.36Si13B12高熵合金的玻璃形成能力、热稳定性和微观结构特征.结果表明,该高熵合金具有良好的玻璃形成能力(GFA)、高的热稳定性以及较高的晶化温度和活化能.DSC曲线表明合金发生两次晶化行为,与此相对应的合金两次晶化产物依次为Co7Fe3相和Fe-B、Co-Si相,而Co7Fe3相结晶会有利于Fe-B、Co-Si相的形成.