The character of the structure formation of model alloys of the Fe-Cr-(Zr, Zr-B) system synthesized by powder metallurgy

2020 ◽  
Vol 2 (100) ◽  
pp. 49-57
Author(s):  
Z.A. Duriagina ◽  
M.R. Romanyshyn ◽  
V.V. Kulyk ◽  
T.M. Kovbasiuk ◽  
A.M. Trostianchyn ◽  
...  
Keyword(s):  
Phase Composition ◽  
Powder Metallurgy ◽  
Chemical Composition ◽  
Structure Formation ◽  
Xrd Analysis ◽  
Model Alloy ◽  
Phase Identification ◽  
Laves Phases ◽  
Cr System ◽  
Sintered Alloys

Purpose: The purpose of the work is to synthesize and investigate the character of structure formation, phase composition and properties of model alloys Fe75Cr25, Fe70Cr25Zr5, and Fe69Cr25Zr5B1. Design/methodology/approach: Model alloys are created using traditional powder metallurgy approaches. The sintering process was carried out in an electric arc furnace with a tungsten cathode in a purified argon atmosphere under a pressure of 6·104 Pa on a water cooled copper anode. Annealing of sintered alloys was carried out at a temperature of 800°C for 3 h in an electrocorundum tube. The XRD analysis was performed on diffractometers DRON-3.0M and DRON-4.0M. Microstructure study and phase identification were performed on a REMMA-102-02 scanning electron microscope. The microhardness was measured on a PMT-3M microhardness meter. Findings: When alloying a model alloy of the Fe-Cr system with zirconium in an amount of up to 5%, it is possible to obtain a microstructure of a composite type consisting of a mechanical mixture of a basic Fe2(Cr) solid solution, solid solutions based on Laves phases and dispersive precipitates of these phases of Fe2Zr and FeCrZr compositions. In alloys of such systems or in coatings formed based on such systems, an increase in hardness and wear resistance and creep resistance at a temperature about 800°C will be reached. Research limitations/implications: The obtained results were verified during laser doping with powder mixtures of appropriate composition on stainless steels of ferrite and ferrite-martensitic classes. Practical implications: The character of the structure formation of model alloys and the determined phase transformations in the Fe-Cr, Fe-Cr-Zr, and Fe-Cr-B-Zr systems can be used to improve the chemical composition of alloying plasters during the formation of ferrite and ferrite-martensitic stainless steel coatings. Originality/value: The model alloys were synthesized and their phase composition and microstructure were studied; also, their microhardness was measured. The influence of the chemical composition of the studied materials on the character of structure formation and their properties was analysed.

scholarly journals Structure Formation of Polycarbide-Based TiC-VC(NbC)-WC/nano WC Hard Alloys

2019 ◽  
Vol 57 ◽  
pp. 35-40 ◽  
Author(s):  
Liudmyla Bodrova ◽  
Halyna Kramar ◽  
Yaroslav Kovalchuk ◽  
Sergiy Marynenko ◽  
Ihor Koval
Keyword(s):  
Chemical Composition ◽  
Tungsten Carbide ◽  
Optical Microscopy ◽  
Structure Formation ◽  
Sintering Temperature ◽  
Xrd Analysis ◽  
Hard Alloys ◽  
Alloying Additions ◽  
The Core

The process of structure formation in the alloys of the system TiC-VC(NbC)-NiCr with the alloying additions of the fine or nano WC, depending on the chemical composition and sintering temperature using the optical microscopy, SEM and XRD analysis, is investigated in this paper. The core/rim structure alloys were found irrespective of the amount of tungsten carbide additions. The research suggests that the adding of nano WC causes decrease in carbide grains, redistribution of the elements in the core and rim, and decrease in sintering temperature by 50–100 °С. Tika pētīts struktūru veidošanas process sakausējumos TiC-VC(NbC)-NiCr ar smalku vai nano WC sakausējuma papildinājumiem atkarībā no ķīmiskā sastāva un saķepināšanas temperatūras, izmantojot optisko mikroskopiju, SEM un XRD analīzi. Centru/aptvērumu struktūras sakausējumi tika konstatēti neatkarīgi no volframa karbīda piedevu daudzuma. Pētījums liecina, ka nano WC pievienošana samazina karbīda graudus, elementu pārdali centros un aptvērumos, kā arī notiek saķepināšanās temperatūras samazināšanās par 50–100° С.

scholarly journals Phase Composition of Iron Ore Sinters Produced with Biomass as a Substitute for the Coke Fuel / Skład Fazowy Spieków Żelaza Wytworzonych Z Dodatkiem Biomasy Jako Zamiennika Dla Koksu

2015 ◽  
Vol 60 (4) ◽  
pp. 2955-2964 ◽  
Author(s):  
R. Mežibrický ◽  
M. Fröhlichová ◽  
A. Mašlejová
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Iron Ore ◽  
Negative Impact ◽  
Thermal Conditions ◽  
Walnut Shell ◽  
Mineral Matter ◽  
Phase Identification ◽  
Mineral Phases ◽  
Key Factor

The effort to minimize CO2 emissions leads the existing integrated steel plants to implement alternative biomass-based fuels that dispose of equilibrium carbon balance. The fuel is a key factor in the iron ore sinter production, so it is essential to know its impact not just on mechanical properties of the finished sintered ore but also on the mineral composition as the mineral phases together determine all observed sinter properties. For this purpose the samples prepared by replacing a part of coke breeze with charcoal or walnut shell substitute were subjected to the observation under the light microscope, also using etching, to the phase identification by chemical EDX analysis on the scanning electron microscope and to the phase composition quantification by X-Ray diffraction analysis. The studied microstructure areas in the vicinity of the pores left by fuel grains were neither characterized by different phases nor by changed chemical composition of these phases even thought mineral matter of the used fuels were substantially different in terms of the chemical composition. The only feature of the burned substitute fuels were ash particles arranged in characteristic shapes. The main reason of variation in ratios of respective mineral phases of samples appeared to be thermal conditions that were reflected in the content of unreacted non-ferrous phases. Coke substitution in the sinter mixture has no negative impact on the phase composition of the produced sinters, which confirms the prospective use of biofuels in the sintering process.

scholarly journals Electrochemical deposition and characterization of Ni-Mo alloy powders

2007 ◽  
Vol 1 (1-2) ◽  
pp. 11-17
Author(s):  
M.G. Pavlovic ◽  
B.M. Jovic ◽  
V.D. Jovic ◽  
U. Lacnjevac ◽  
V.M. Maksimovic
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Concentration Ratio ◽  
Xrd Analysis ◽  
Crystalline Powder ◽  
Powder Composition ◽  
Eds Analysis ◽  
N2 Atmosphere ◽  
Powder Particles

Electrodeposition of Ni-Mo alloy powders from ammonium sulfate and ammonium chloride containing electrolytes of different Ni/Mo ions concentration ratios was investigated by polarization measurements. The morphology, chemical composition and phase composition of electrodeposited Ni-Mo alloy powders were investigated using DSC, TGA, SEM, EDS and XRD analysis. EDS results showed that powder composition depends on Ni/Mo ions concentration ratio, as well as on the position where the EDS analysis was performed. As-deposited alloy powders were nanocrystalline showing no XRD peaks with undefined morphology (SEM). After recrystallization for 2 h in N2 atmosphere at 600?C the presence of NiMoO4 phase was identified in the powder electrodeposited from chloride electrolyte at the Ni/Mo ions concentration ratio 1/3, with well defined crystalline powder particles.

scholarly journals An Insight into Chemistry and Structure of Colloidal 2D-WS2 Nanoflakes: Combined XPS and XRD Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1969
Author(s):  
Riccardo Scarfiello ◽  
Elisabetta Mazzotta ◽  
Davide Altamura ◽  
Concetta Nobile ◽  
Rosanna Mastria ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Xrd Analysis ◽  
Crystal Habit ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Evaluation ◽  
Rational Understanding ◽  
Structural Inspection

The surface and structural characterization techniques of three atom-thick bi-dimensional 2D-WS2 colloidal nanocrystals cross the limit of bulk investigation, offering the possibility of simultaneous phase identification, structural-to-morphological evaluation, and surface chemical description. In the present study, we report a rational understanding based on X-ray photoelectron spectroscopy (XPS) and structural inspection of two kinds of dimensionally controllable 2D-WS2 colloidal nanoflakes (NFLs) generated with a surfactant assisted non-hydrolytic route. The qualitative and quantitative determination of 1T’ and 2H phases based on W 4f XPS signal components, together with the presence of two kinds of sulfur ions, S22− and S2−, based on S 2p signal and related to the formation of WS2 and WOxSy in a mixed oxygen-sulfur environment, are carefully reported and discussed for both nanocrystals breeds. The XPS results are used as an input for detailed X-ray Diffraction (XRD) analysis allowing for a clear discrimination of NFLs crystal habit, and an estimation of the exact number of atomic monolayers composing the 2D-WS2 nanocrystalline samples.

A data-driven XRD analysis protocol for phase identification and phase-fraction prediction of multiphase inorganic compounds

2021 ◽  
Author(s):  
Jin-Woong Lee ◽  
Woon Bae Park ◽  
Minseuk Kim ◽  
Satendra Pal Singh ◽  
Myoungho Pyo ◽  
...  
Keyword(s):  
Deep Learning ◽  
Inorganic Compounds ◽  
Xrd Analysis ◽  
Data Driven ◽  
Phase Fraction ◽  
Phase Identification ◽  
Constituent Phase ◽  
Analysis Protocol

Deep learning (DL) models trained with synthetic XRD data have never accomplished a satisfactory quantitative XRD analysis for the exact prediction of a constituent-phase fraction in unknown multiphase inorganic compounds,...

Microstructure and Creep Properties of Selected Gravity Casting Magnesium Alloys

2016 ◽  
Vol 682 ◽  
pp. 372-379
Author(s):  
Tomasz Rzychoń
Keyword(s):  
Magnesium Alloys ◽  
Creep Resistance ◽  
Low Cost ◽  
Xrd Analysis ◽  
Phase Identification ◽  
Creep Tests ◽  
Gravity Casting ◽  
Creep Properties ◽  
Transmission Electron ◽  
Primary Crystals

In this paper microstructure and creep properties of Mg-Al-Ca-Sr, Mg-Zn-RE-Zr and Mg-Sn-Si gravity casting magnesium alloys are presented. The microstructure was characterized using light microscopy, scanning and transmission electron microscopy. Phase identification was made by SAED and XRD analysis. Creep tests were carried out in the temperature range from 180°C to 200°C at applied stress of 60 MPa. Microstructure of Mg-Al-Ca-Sr alloys composed of α-Mg grains and C36, C15 and C14 intermetallic compounds in the interdendritic regions. In case of Mg-Zn-RE-Zr alloys the dominant intermetallic compound is (Mg,Zn)12RE phase also located in the interdendritic regions. Microstructure of Mg-Sn-Si alloys after T6 heat treatment consists of plate-like precipitates of Mg2Sn phase, primary crystals of Mg2Si phase and globular Mg2Si phase. Among the alloys in this study, the low-cost Mg-5Al-3Ca-0.7Sr alloy has the best creep resistance. The other alloys, excluding the Mg-5Si-7Sn alloy, are characterized by a poorer creep resistance in compared to Mg-5Al-3Ca-0.7Sr alloy, however their creep resistance is better if compared to typical Mg-Al alloys. Creep resistance of Mg-5Si-7Sn alloy is very low.

scholarly journals Study on the nonexistence of liquid miscibility gap in the Ce-Mn system

2007 ◽  
Vol 43 (1) ◽  
pp. 21-28 ◽  
Author(s):  
C. Tang ◽  
Y. Du ◽  
H. Xu ◽  
S. Hao ◽  
L. Zhang
Keyword(s):  
Xrd Analysis ◽  
Miscibility Gap ◽  
Composition Analysis ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Observation ◽  
Arc Melting ◽  
Ice Water ◽  
Liquid Miscibility Gap

To ascertain whether the liquid miscibility gap exists in the Ce-Mn system, 3 key alloys are prepared by arc melting the pure elements, annealed at specified temperature for 20 minutes, quenched in ice water and then subjected to X-ray diffraction (XRD) analysis for phase identification and to scanning electron microscopy (SEM) with energy dispersive X-ray analysis for microstructure observation and composition analysis. The XRD examination indicated that terminal solutions based on Ce and Mn exist in the water-quenched alloys. No compound was detected. Microstructure observation and composition analysis indicate the nonexistence of the liquid miscibility gap. The newly assessed Ce-Mn phase diagram was presented. .

scholarly journals Production and investigation of powders for additive synthesis from a new beta-solidifying TiAl-based alloy

2021 ◽  
Vol 2144 (1) ◽  
pp. 012004
Author(s):  
P V Panin ◽  
I A Bogachev ◽  
E A Lukina
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Equilibrium Phase ◽  
Fold Increase ◽  
Induction Melting ◽  
Technological Properties ◽  
Powder Flowability ◽  
Powder Particles ◽  
Additive Synthesis ◽  
Composition Structure

Abstract Chemical composition, structure, and technological properties have been investigated for metal powder compositions (MPCs) of a new six-component TiAl-based alloy with Gd microadditions: Ti-31.0Al-2.5V-2.5Nb-2.5Cr-0.4Gd, wt.% (Ti-44.5Al-2V-1Nb-2Cr-0.1Gd, at.%). Three MPCs fractions (10–63, 40–100, 80–120 μm) were produced by electrode induction melting and inert gas atomization technique and targeted for the additive synthesis of parts. It is shown that the chemical composition of the MPCs for the main elements corresponds to that of the electrode. In contrast, a 1.5-fold increase of the oxygen content in the MPCs was observed, which is being the result of natural oxidation of powder particles upon air environment due to developed specific surface. It has been determined that the phase composition of the MPCs (γ+α(α2)+β) differs from the equilibrium phase composition of the electrode (γ+α2)+β0/B2) and corresponds to a rapidly quenched metastable state, which indicates high solidification rates in the atomization process, exceeding critical cooling rates of the alloy. The technological properties, specifically the powder flowability, were found to be improved for 40–100 and 80–120 μm fractions, making them applicable for additive synthesis of parts from the studied alloy by selective electron-beam melting method

scholarly journals X-ray diffraction analysis of MTA-Plus, MTA-Angelus and DiaRoot BioAggregate

2014 ◽  
Vol 08 (02) ◽  
pp. 211-215 ◽  
Author(s):  
Yeliz Guven ◽  
Elif Bahar Tuna ◽  
Muzaffer Emin Dincol ◽  
Oya Aktoren
Keyword(s):  
Crystal Structure ◽  
Tantalum Oxide ◽  
Xrd Analysis ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Glass Slide ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tricalcium Aluminate

ABSTRACT Objective: The purpose of this study was to investigate and compare the crystalline structures of recently released MTA Plus (MTA-P), MTA Angelus (MTA-A), DiaRoot BioAggregate (BA) by X-ray diffraction (XRD) analysis. Materials and Methods: Phase analysis was carried out on powder and set forms of tested materials. The powder specimens placed into sample holders that were packed with a glass slide and the set samples prepared according to the manufacturer's instructions were placed into molds. The samples after being set for three days at 37°C and 100% humidity in an incubator were mounted onto the XRD machine and phase identification was accomplished using a search-match software program. Results: XRD findings indicated that major constituents of MTA-P were bismuth oxide, portlandite, dicalcium silicate and tricalcium silicate. The crystal structure of MTA-A were similar to those of MTA-P except for the absence of portlandite. Additionally, MTA-A had tricalcium aluminate differing from MTA-P. BA mainly differed from MTA-P and MTA-A by the radiopacifier (tantalum oxide-TO) in its composition. Conclusions: The majority of constituents of the tested materials have shown similarity except for the presence of tricalcium aluminate in MTA-A and the inclusion of TO in BA. In addition, set MTA-P showed a strong peak of portlandite.

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