Incipient flow properties of two-component fine powder mixtures: Changing the flowability of smaller particles

The focus of new technologies on the formation of inhomogeneous distributions of heavy rare-earth metals (REMs) in hard magnetic Nd–Fe–B materials is of scientific importance to increase their functional properties, along with preserving existing sources of heavy REMs. This paper focused on the coercivity enhancement of Nd2Fe14B-based magnets by optimizing the microstructure, which includes the processes of grain boundary structuring via the application of a Dy3Co0.6Cu0.4Hx alloy added to the initial Nd–Fe–B-based powder mixtures in the course of their mechanical activation. We have studied the role of alloying elements in the formation of phase composition, microstructure, the fine structure of grains, and the hysteretic properties of hard magnetic Nd(R)2Fe14B-based materials. It was shown that the Dy introduction via the two-component blending process (the hydrogenated Dy3Co0.6Cu0.4 compound is added to a powder mixture) resulted in the formation of the core-shell structure of 2–14–1 phase grains. The efficient improvement of the coercivity of Nd(RE)–Fe–B magnets, with a slight sacrifice of remanence, was demonstrated.

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Inference on accretion flow properties of XTE J1752-223 during its 2009-10 outburst

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa391 ◽

2020 ◽

Vol 493 (2) ◽

pp. 2452-2462 ◽

Cited By ~ 2

Author(s):

Kaushik Chatterjee ◽

Dipak Debnath ◽

Debjit Chatterjee ◽

Arghajit Jana ◽

Sandip K Chakrabarti

Keyword(s):

Black Hole ◽

Spectral Analysis ◽

Low Frequency ◽

Power Law Model ◽

Flow Properties ◽

Advective Flow ◽

Black Hole Candidate ◽

Two Component ◽

Timing Properties ◽

Spectral States

ABSTRACT Spectral and timing properties of the stellar-mass black hole candidate XTE J1752-223 during its 2009-10 outburst are studied using RXTE PCA data in the 2.5–25 keV energy range. Low frequency quasi-periodic oscillations are seen during outburst. The spectral analysis is done using two types of models: one is the combined disc blackbody plus power-law model and the other is Transonic flow solution based Two Component Advective Flow (TCAF) model. Light-curve profiles and evolution of hardness ratios are studied using MAXI GSC and Swift BAT data. Based on the evolution of the temporal and the spectral properties, we find that the object evolved through the following spectral states: hard, hard-intermediate, and soft-intermediate/soft. From the TCAF model fitted spectral analysis, we also estimate the probable mass of the black hole in the range of 8.1−11.9 M⊙, and more precisely, the mass appears to be 10 ± 1.9 M⊙.

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Complex metallophysical studies of structural steels after two-component diffusion hardening based on boron

10.33920/pro-2-2109-02 ◽

2021 ◽

pp. 18-24

Author(s):

V.M. Roshchupkin ◽

Yu.V. Skripkina ◽

V.N. Gadalov ◽

O.M. Gubanov

Keyword(s):

Brittle Failure ◽

Structural Steels ◽

Dynamic Effects ◽

English Version ◽

Surface Layers ◽

Powder Mixtures ◽

Wear Process ◽

Two Component ◽

Structure Phase ◽

Boride Phases

The studies of the structure, phase composition and microhardness of 45; 40X13 and (25...30) CMT steels during hardening in mixtures containing boron, boron and silicon, as well as boron, silicon and aluminum, are presented. Boration was carried out at a temperature of 890°C for 3 hours. The results of the study show that as a result of boration, the layer thickness is greater than in the case of borosiliconizing and boro-alumino-siliconizing, however, the needles of the boride phases are sharper. By obtaining diffusive layers that differ in structure with different phase ratios FeB, Fe2 B, Fe3 Si, it is possible to significantly influence the resistance to brittle failure of the surface layers of parts that are operated under real conditions in friction pairs under periodic or constant shock effects. So, if the wear process proceeds without ever manifesting dynamic effects, then it is possible to recommend the use of the boration process – both for small-sized parts with CTR in powder mixtures using unpressurized containers, and large-sized parts - in coatings that are applied only to the wearing surfaces of the parts. If the wear occurs under conditions of a relatively low level of periodically manifested shock effects, it is possible to use the borosiliconizing process at (800...900)°C. English version of the article is available at URL: https://panor.ru/articles/complex-metal-physical-studies-of-structural-steels-after-twocomponent-boron-based-diffusion-hardening/69778.html

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