Solubility of carbon, manganese and silicon in γ-iron of Fe-Mn-Si-C alloys

The study was performed on alloys with a carbon content of 0,37-0,57 % (wt.), silicon 0,23-0,29 % (wt.), manganese 0,7-0,86 % (wt.), the rest– iron. To determine the phase composition of alloys used microstructural, microanalysis and X-ray analysis. In addition, the physical characteristics of the alloys studied in this paper were determined, such as alloy chemical dependence of extension and contraction ratio, impact toughness and hardness. The results obtained in this paper showed that the iron-based alloy with the content of carbon of 0.57 % (wt.), silicon of 0.28 % (wt.) and manganese of 0.86 % (wt.)) had the superior microstructure and physical properties. It was determined that after a number of crystallization and phase transformation the alloy phase structure includes two phases: a-iron and cement magnesium doping Fe2.7Mn0,3C.. For the first time using the method quasichemistry received an expression of the free energy of a γ-iron alloyed with silicon and magnesium, and determined the solubility limit of carbon, manganese and silicon. The maximum content in γ-iron can reach: carbon 6,8 % (at.), manganese – 67,5 % (at.), silicon – 2,3 % (at.).

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Solubility of Carbon, Manganese and Silicon in α-Iron of Fe-Mn-Si-C Alloys

East European Journal of Physics ◽

10.26565/2312-4334-2020-4-12 ◽

2020 ◽

Keyword(s):

Solid Solution ◽

Free Energy ◽

Solubility Limit ◽

Chemical Dependence ◽

X Ray ◽

Contraction Ratio ◽

Iron Based ◽

Two Phases ◽

First Time ◽

Maximum Content

The study was performed on alloys with a carbon content of 0.37-0.57% (wt.), silicon 0.23-0.29% (wt.), manganese 0.7‑0.86% (wt.), the rest– iron. To determine the phase composition of alloys used microstructural, microanalysis and X-ray analysis. In addition, the physical characteristics of the alloys studied in this paper were determined, such as alloy chemical dependence of extension and contraction ratio, impact toughness and hardness. The results obtained in this paper showed that the iron-based alloy with the content of carbon of 0.57 % (wt.), silicon of 0.28 % (wt.) and manganese of 0.86 % (wt.)) had the superior microstructure and physical properties. It was determined that after a number of crystallization and phase transformation the alloy phase structure includes two phases: a-iron and cement magnesium dopingFe2.7Mn0,3C. For the first time using the method quasi-chemistry received an expression of the free energy of a solid solution α-iron alloyed with silicon and magnesium, and determined the solubility limit of carbon, manganese and silicon. In δ-iron may dissolve to 0.09% (wt.) carbon, manganese up to 3.5% (wt.), silicon – 0.25% (wt.). The maximum content in α-iron can reach: carbon – 0.017% (wt.), manganese – 21% (wt.), silicon – 1.3% (wt.).

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Investigation of Silicon and Manganese Solubility in Cementite of Iron-Based Alloys

East European Journal of Physics ◽

10.26565/2312-4334-2019-2-07 ◽

2019 ◽

Keyword(s):

Free Energy ◽

Physical Properties ◽

Carbon Content ◽

Manganese Content ◽

Calculated Data ◽

Volume Ratio ◽

X Ray Diffraction ◽

Contraction Ratio ◽

Crucible Furnace ◽

Iron Based

In the paper we obtained the expression of cementite free energy and determined the solubility of manganese and silicon in Fe3C cementite depending on the temperature. Investigation was carried out for alloys with carbon content of 0.55-0.60 % (wt.), silicon content of 0.95-1.0 % (wt.), manganese content of 0.8-0.9% (wt.), the rest was iron. The smelting of Fe-Mn-Si-C system alloys was carried out in the alundum crucible furnace in argon atmosphere. The cooling rate of alloys after casting was 10 K/s. Microstructure analysis along with X-ray diffraction analysis was used to determine the structural state of the alloys. In addition, the physical characteristics of the alloys studied in this paper were determined, such as alloy chemical dependence of ultimate strength, extension and contraction ratio, impact toughness and hardness. The results obtained in this paper showed that the iron-based alloy with the content of carbon of 0.57 % (wt.), silicon of 0.97 % (wt.) and manganese of 0.85 % (wt.)) had the superior microstructure and physical properties. The microstructure of alloys studied in the paper is represented by pearlite, which makes up to 95 % of the volume. In the alloys we revealed the highly dispersed inclusions of Fe2.7Mn0.3C, Fe0.25Mn1.4C0.6 and Fe9SiC0.4 carbides, whose volume ratio was up to 1.5 %, the rest was ferrite. As it is known, the structural constituent of pearlite is cementite. The cementite has a significant effect on the physical properties of alloys. Application of quasi-chemical method enables to calculate the free energy of silicon and manganese doped with cementite and to determine the temperature dependence of silicon and manganese content in cementite. It is ascertained that there is a slight increase of carbon content in cementite (up to 28.79 % (atoms). Manganese can replace up to 12 % of iron atoms, and silicon can replace up to 4.5 % of iron atoms, depending on temperature. The calculated data obtained in this paper are in good agreement with those found experimentally by other authors.

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Non-negative matrix factorization for the near real-time interpretation of absorption effects in elemental distribution images acquired by X-ray fluorescence imaging

Journal of Synchrotron Radiation ◽

10.1107/s1600577515023528 ◽

2016 ◽

Vol 23 (2) ◽

pp. 579-589 ◽

Cited By ~ 6

Author(s):

Matthias Alfeld ◽

Mirwaes Wahabzada ◽

Christian Bauckhage ◽

Kristian Kersting ◽

Gerd Wellenreuther ◽

...

Keyword(s):

Real Time ◽

Matrix Factorization ◽

Fluorescence Analysis ◽

Alloy System ◽

Data Sets ◽

Elemental Distribution ◽

X Ray ◽

Two Phases ◽

First Time ◽

Non Negative Matrix Factorization

Elemental distribution images acquired by imaging X-ray fluorescence analysis can contain high degrees of redundancy and weakly discernible correlations. In this article near real-time non-negative matrix factorization (NMF) is described for the analysis of a number of data sets acquired from samples of a bi-modal α+β Ti-6Al-6V-2Sn alloy. NMF was used for the first time to reveal absorption artefacts in the elemental distribution images of the samples, where two phases of the alloy, namely α and β, were in superposition. The findings and interpretation of the NMF results were confirmed by Monte Carlo simulation of the layered alloy system. Furthermore, it is shown how the simultaneous factorization of several stacks of elemental distribution images provides uniform basis vectors and consequently simplifies the interpretation of the representation.

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Improved powder diffraction patterns for synthetic paranatisite and natisite

Powder Diffraction ◽

10.1154/1.1483323 ◽

2002 ◽

Vol 17 (3) ◽

pp. 234-237 ◽

Cited By ~ 7

Author(s):

S. Ferdov ◽

V. Kostov-Kytin ◽

O. Petrov

Keyword(s):

Data Interpretation ◽

X Ray Diffraction ◽

Orthorhombic Space Group ◽

Space Group ◽

X Ray ◽

Cell Parameters ◽

Diffraction Patterns ◽

Two Phases ◽

Xrd Patterns ◽

First Time

Synthetic analogues of the minerals natisite and for the first time of paranatisite were prepared hydrothermally at 200 °C in the system Na2O–TiO2–SiO2–H2O. The obtained powder x-ray diffraction (XRD) patterns were interpreted by the Powder Data Interpretation (PDI) software package. As a result improved indexing and unit cell parameters refinements of these two phases were achieved. Synthetic natisite is tetragonal, space group—P4/nmm, a=0.649 67(8) nm, c=0.508 45(11) nm, V=0.214 50(10) nm3, Z=2, Dcal=3.13 g.cm−1, F30=37.48, M20=52.79. Synthetic paranatisite is orthorhombic, space group—Pmma, a=0.983 86(29) nm, b=0.919 23(19) nm, c=0.481 84(12) nm, V=0.435 78(19) nm3, Z=1, Dcal=3.01 g.cm−1, F30=16.42, M20=29.21.

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New Insights on the Stradivari “Coristo” Mandolin: A Combined Non-Invasive Spectroscopic Approach

Applied Sciences ◽

10.3390/app112411626 ◽

2021 ◽

Vol 11 (24) ◽

pp. 11626

Author(s):

Francesca Volpi ◽

Giacomo Fiocco ◽

Tommaso Rovetta ◽

Claudia Invernizzi ◽

Michela Albano ◽

...

Keyword(s):

Ir Spectroscopy ◽

String Instruments ◽

X Ray ◽

Non Invasive ◽

Ft Ir ◽

Iron Based ◽

Materials Used ◽

First Time ◽

Violin Making ◽

Ft Ir Spectroscopy

In this work, one of the two existing mandolins made by Antonio Stradivari has been investigated for the first time, as a rare exemplar of the lesser-known class of plucked string instruments. The mandolin was studied by non-invasive reflection Fourier transformed infrared (FT-IR) spectroscopy and X-ray fluorescence (XRF) on different areas previously selected by UV-induced fluorescence imaging. The analytical campaign was aimed at (i) identifying the materials used by Stradivari in the finishing of the mandolin, (ii) comparing these materials with those traditionally used in violin making, and (iii) increasing the knowledge of materials and techniques applied by Stradivari in the rare production of plucked string instruments. The combined spectroscopic approach allowed us to hypothesize original materials and finishing procedures similar to those used in violin making: a possible sizing treatment of the wood with protein-based materials and silicates, externally coated with an oil–resin varnish. XRF results were essential to support FT-IR findings and to detect possible iron-based pigments in the finishing layers. Moreover, it permitted us to distinguish original areas from the restored areas, including the purflings on the top plate and the varnished area on the treble side of the mandolin for which the originality was assumed.

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Solubility of boron and carbon in γ-iron of Fe-B-C alloys

Journal of Physics and Electronics ◽

10.15421/331905 ◽

2019 ◽

Vol 27 (1) ◽

pp. 31-36

Author(s):

N. Yu. Filonenko ◽

A. N. Galdina

Keyword(s):

Phase Composition ◽

Boron Content ◽

Vertical Section ◽

State Diagram ◽

Solidification Process ◽

Weight Fraction ◽

Solubility Limit ◽

Maximum Weight ◽

X Ray ◽

First Time

It is known that solubility of elements affects the phase composition of alloys that are formed in the solidification process. To predict the phase composition of alloys, it is necessary to determine the solubility limit in the phases. In the paper the structural properties of austenite of alloys in the system of Fe-B-C are studied and the solubility limit of boron and carbon is determined. The investigation is carried out for the specimens with carbon content of 0.0001–2.3 wt.% and boron content of 0.0001–1.0 wt.%, the rest is iron. To determine the physical properties of alloys, we use the microstructure analysis, X-ray microanalysis, X-ray structure analysis and differential thermal analysis. It is shown experimentally that the maximum shift of the eutectoid point is observed when boron content is up to 0.004 wt.%. When boron content of the alloy increases to 0.01 wt.%, the eutectoid point shifts to the left to 0.21 wt.%-carbon and the austenite area decreases. Further increase in the numerical value of boron content in the alloy is hardly caused the eutectoid point to shift. In this paper, the vertical section of the Fe-B-C system state diagram is obtained from experimental data. For the first time we obtain temperature dependence of the free energy of γ-iron solid solution, using the quasi-chemical method, and determine the solubility limit of carbon and boron. The maximum weight fraction of boron in the austenite can be up to 0.0136 wt.%, and that for carbon – up to 1.12 wt.%.

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Solubility of Boron and Carbon in Ferrite of the Fe-B-C System Alloys

East European Journal of Physics ◽

10.26565/2312-4334-2019-2-08 ◽

2019 ◽

Keyword(s):

Solid Solution ◽

Carbon Content ◽

Mass Fraction ◽

Room Temperature ◽

Boron Content ◽

Solubility Limit ◽

Content Increase ◽

X Ray ◽

First Time ◽

Structure Imperfection

Investigation was carried out for Fe-B-C alloys with carbon content of 0.0001–0.01 % (wt.) and boron content of 0.0001–0.01 % (wt.), the rest is iron. To determine the structural state of alloys we use the microstructure analysis, X-ray microanalysis and X-ray structure analysis. The level of microstraines, dislocation density and the coercive force of ferrite is determined, and it is shown that structure imperfection grows with boron content increase in the alloy. The obtained results enable to suggest that boron atoms in a solid solution of α-iron occupy substitutional-interstitial positions depending on boron content. In the paper it is shown experimentally, that at room temperature solubility limit of boron and carbon in the ferrite is 0.00012 % (wt.) and 0.006 % (wt.). When boron and carbon content increases further, the following phases are formed: Fe2B, Fe3(CB) and Fe23(CB)6. In this paper by means of quasi-chemical method we obtain for the first time temperature dependence of the free energy for α-iron solid solution, as well as solubility limit of carbon and boron. Maximum mass fraction of carbon may be up to 0.016 % (wt.), and maximum boron mass fraction – up to 0.00025 % (wt.). At room temperature the boron solubility limit in ferrite is 0.0001 % (wt.), and carbon one is 0.004 % (wt.). The calculated numerical values of the solubility of boron and carbon in ferrite of the Fe-B-C system alloys are less than that of the experimental results. This can be explained by the fact that boron atoms interact more actively with structure imperfections than carbon atoms. At high temperatures the solubility of carbon and boron in given phase increases.

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Imaging of Al-Li-Cu alloys with a Scanning Ion Microprobe

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135174 ◽

1990 ◽

Vol 48 (2) ◽

pp. 314-315

Author(s):

K.K. Soni ◽

D.B. Williams ◽

J.M. Chabala ◽

R. Levi-Setti ◽

D.E. Newbury

Keyword(s):

Mass Spectrometry ◽

Secondary Ion Mass Spectrometry ◽

Equilibrium Phase ◽

Icosahedral Symmetry ◽

Ion Microprobe ◽

X Ray ◽

Cu Alloys ◽

Two Phases ◽

The University ◽

Secondary Ion

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.

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Defect structures of Nb1+αS2 sulfidation scales

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012059x ◽

1992 ◽

Vol 50 (1) ◽

pp. 38-39

Author(s):

Chuxin Zhou ◽

L. W. Hobbs

Keyword(s):

Stacking Faults ◽

Rhombohedral Structure ◽

Stacking Sequence ◽

Defect Structures ◽

X Ray Diffraction ◽

X Ray ◽

Plane Normal ◽

Lower Case ◽

Sulfur Layer ◽

Two Phases

One of the major purposes in the present work is to study the high temperature sulfidation properties of Nb in severe sulfidizing environments. Kinetically, the sulfidation rate of Nb is satisfactorily slow, but the microstructures and non-stoichiometry of Nb1+αS2 challenge conventional oxidation/sulfidation theory and defect models of non-stoichiometric compounds. This challenge reflects our limited knowledge of the dependence of kinetics and atomic migration processes in solid state materials on their defect structures.Figure 1 shows a high resolution image of a platelet from the middle portion of the Nb1+αS2 scale. A thin lamellar heterogeneity (about 5nm) is observed. From X-ray diffraction results, we have shown that Nb1+αS2 scale is principally rhombohedral structure, but 2H-NbS2 can result locally due to stacking faults, because the only difference between these 2H and 3R phases is variation in the stacking sequence along the c axis. Following an ABC notation, we use capital letters A, B and C to represent the sulfur layer, and lower case letters a, b and c to refer to Nb layers. For example, the stacking sequence of 2H phase is AbACbCA, which is a ∼12Å period along the c axis; the stacking sequence of 3R phase is AbABcBCaCA to form an ∼18Å period along the c axis. Intergrowth of these two phases can take place at stacking faults or by a shear in the basal plane normal to the c axis.

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