International Journal of Self-Propagating High-Temperature Synthesis最新文献

Macrokinetic parameters of combustion of powder and granular mixtures were studied upon dilution of Ti + C with various metal powders. The combustion velocities of powder mixtures (Ti + C) + 20% Me (Me = Ni, Cu) turned out to be higher than those of Ti + C blend, despite the lower temperature of combustion. When diluting Ti + C mixture with Ti or TiC powders, there was no such a contradiction. The convective-conductive model of combustion explains obtained data by a strong influence of impurity gas release from titanium particles ahead the combustion front. The time of combustion transfer between the granules, the combustion velocity inside the granules, and the quantitative assessment of the retarding effect of impurity gases in powder mixtures were determined. When comparing the combustion parameters of granular Ti + C mixtures diluted with various metal powders and titanium carbide, the efficiency of the combustion transfer between the granules in the presence of hot Ni melt was explained. In addition, the impurity gas reabsorption by titanium carbide was confirmed.

We report the use of high-energy cryo-milling for fabrication of reactive composite Ni/Al particles. Specifically, the CryoMill (Retsch) with liquid nitrogen was used with milling times in the range of 5 to 40 min. The microstructure of the obtained particles and their ignition characteristics were investigated. A novel bifurcated ignition mode for intermediate milling times was observed. The correlations between the microstructure of the Ni/Al particles and their reactivity were discussed.

Finding new energy effective methods for the production of refractory multi-principal element alloys (MPEAs) is a challenge for rapidly developing MPEA materials science. Formation of equimolar TiZrHfVNb MPEA and evaluation of alloy potential for use as hydrogen storage material were investigated. In this study, we demonstrated, for the first time to the best of our knowledge, that MPEA can be produced using SHS hydrides as precursor materials by “Hydride Cycle” (HC) method. The hydrogenation of obtained alloy by self-propagating high-temperature synthesis (SHS) method was studied. Crystal structure, surface microstructure, chemical composition, and thermal stability of synthesized materials were studied. It was shown that two-phase (α + β) alloy was synthesized. As a result of the SHS hydrogenation process, TiZrHfVNb alloy absorbed 1.8 wt % of hydrogen.

In this paper, we presented structural, Fourier infrared spectroscopic, and dielectric analysis of cobalt chromate (Co²⁺({text{Cr}}_{2}^{{3 + }})O₄) with 2 mol % of gadolinium (Gd³⁺) rare earth metal additions under humidity and non-humidity circumstances. The Gd³⁺ doped Co²⁺({text{Cr}}_{2}^{{3 + }})O₄ samples were prepared by solution combustion method and sintered for 2 h at 650°C to get single phase. Doped and undoped samples were characterized by X-ray powder diffraction (XRD) analysis providing the detailed information of the Co²⁺({text{Cr}}_{2}^{{3 + }})O₄ phase and crystallinity. Furthermore, the average crystallite sizes were found to be in the range of 18 to 7 nm. The general nature of ferrite materials was revealed via FTIR analysis. The octahedral and tetrahedral stretching band in FTIR spectra were confirmed a ferrite structure without impurity. Scanning electron microscopic images exhibited that samples are highly porosity. We investigated the relevant conductivity of the samples, the reaction time of the capacitive sensor, and the humidity influence on the relative permittivity characteristics at a constant frequency of 1 kHz. Our findings indicate that Gd³⁺ doped Co²⁺({text{Cr}}_{2}^{{3 + }})O₄ could be exploited as an active material in humidity sensor applications.

(Ti–Al–Mn)/Ti metal–intermetallic layered material was prepared by SHS pressing. It was found that the combustion product obtained in Ti–Al–Mn layer consists of hexagonal Ti(Mn_0.755Al_1.246) and cubic Ti_0.25Al_0.67Mn_0.08 phases. The transition zone forming between the Ti–Al–Mn layer and the Ti foil was shown to have a thickness of 10–15 µm and to be represented by Ti_xAl phase with variable composition.

In the present work, CuEu_0.01Fe_1.99O₄ and CuEu_0.01Sc_0.01Fe_1.98O₄ nanoparticles were prepared by self-propagating high-temperature synthesis method for reporting the structural, microstructural, and magnetic properties of prepared samples. X-ray diffraction (XRD) patterns confirmed the spinel cubic structure with space group Fd3m. An average crystallite size was found in the range of 20–40 nm. Scanning electron microscopy (SEM) investigations indicated the porous nature and particles agglomeration. The elemental composition of samples was studied by using energy-dispersive X-ray spectroscopy (EDS). The magnetic hysteresis loop revealed the soft ferromagnetic nature. Magnetic parameters such as saturation magnetization, coercivity, and remanence magnetization decrease with an increase in Eu³⁺ and Sc³⁺ concentration.