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The microstructure, precipitation behavior, strengthening under thermo-mechanical treatment, recrystallization behavior, and internal friction response to recrystallization, mechanical properties, and electrical conductivity of the Al-0.3Zr-0.3Sm with 0.5Fe and 0.5Si impurities were investigated in detail. The Si and Fe impurities in the Al-0.3Zr-0.3Sm alloy are distributed between A8Fe2Si and tau 1-Al2Si2Sm phases in the as-cast structure. Zirconium, samarium, and silicon atoms dissolved in the Al solid solution under solidification provide formation of L12-structured Al3(Sm,Zr), alpha-Al8Fe2Si quasicrystal and Si precipitates under annealing at 360 degrees C for 10 h. The impurities accelerate the reaching of hardness peak from 50 to 100 h to 10 h. Additionally Sm speeds up hardening and an increase in hardness in compare the alloys with impurities and without Sm due to L12-Al3(Sm,Zr) precipitates with average diameter of 4 +/- 0.5 nm. Technologies of the thermo-mechanical treatment included preaging to the highest strengthening, rolling and annealing provide achieving an excellent combination of strength and electrical conductivity due to more complex decomposition of Al solid solution. The pseudo internal friction peak depends on thermo-mechanical treatment: the peak temperatures are 432, 462, 418, and 471 degrees C (for f=1 Hz) for the samples obtained by T1, T2, T3 and T4 technologies, correspondingly. A grain boundary peak with typical for Al alloys apparent and true activation parameters was recorded for all samples after heating to 500 degrees C (full recrystallization) during TDIF measurements. The novel alloy is a good prospective for electrical conductor with possible using of the cheapest Al in the production.
Transient and thermally activated anelastic effects between 0 and 800 degrees C are studied in in a Fe-26.6at%Ga alloy using bending and torsion forced vibrations and measuring the mechanical loss ant the elastic modulus. The structure characterization and transformations are studied by in situ neutron diffraction. The phase morphology and grain crystal structure are investigated by EBSD. Vibrating sample magnetometry accompanies those measurements providing the magnetic susceptibility that characterize the phases appearing as a function of the temperature. Two thermally activated and three transient anelastic effects are reported. They are discussed in detail with respect to structure and phase transitions in the alloy. Four main phases are found: D03, L12, D019 and A2. Each transformation between these phases is characterized by a transient mechanical loss peak and a modulus variation. The thermally activated relaxations named P1 and P2 are respectively a Snoek and a Zener relaxations and they are related to the presence of the metastable D03 phase.
This study investigates in-situ TiN formation in WC-Co-Ti composites processed by high-energy ball milling, gas-phase nitridation, and spark plasma sintering (SPS). The optimized composite was consolidated by SPS at a peak temperature of 1250 degrees C, a holding time of 10 min, and an applied pressure of 50 MPa. Based on XRD phase evolution in nitrided powders and SEM/EDS observations of the consolidated microstructure, a diffusion-assisted formation pathway is proposed, in which nitrogen transport through the binder/interface region promotes TiN formation near Ti-containing domains and WC-binder interfaces. The resulting Ti-N-enriched interfacial regions contribute to localized WC grain-growth suppression and influence fracture behavior through crack deflection at heterogeneous interfaces. The optimized composite achieved a Vickers hardness of similar to 1870 HV and a fracture toughness of 6.8 MPam(1/2). These results establish gas-phase nitridation combined with SPS as an effective route to introduce Ti-N-enriched interfacial regions and tailor the phase/microstructure of WC-Co-based cemented carbides, leading to an improved hardness-toughness balance.
This study investigates the influence of Praseodymium (Pr) additions (0.0–1.0 wt.
Rare-earth tritellurides RTe3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{3}$$\end{document} exhibit a wide spectrum of electronic proprieties, ranging from charge density wave (CDW) phenomena to superconductivity. Angle-resolved photoemission spectroscopy (ARPES) is a valuable technique for probing alterations in band structure and symmetry associated with CDW formation. Although ARPES offers several advantages, acquiring an accurate two-dimensional band map in the momentum space is always challenging. In this paper, we use image processing techniques on ARPES data to precisely calculate the size of the residual electron pockets in RTe3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{3}$$\end{document} compounds. Then, the results are compared with measurements of slow quantum oscillations to evaluate their nature at temperatures below the second CDW transition, TCDW2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{\text {CDW2}}$$\end{document}. The close correspondence between the two approaches clarifies the nature of the surviving metallic states and demonstrates the utility of image segmentation methods for refining ARPES-based electronic structure analysis.
