Synchrotron X-ray diffraction evidences of the amorphization/dissolution of the second phase particles (SPPs) in neutron irradiated Zircaloy-4

The Nano-HA powder were synthesized by chemical precipitation with Ca(H2PO4)2•H2O and Ca (OH)2 and porous HA was prepared by sintering with magnesium as pore-creator. Nano-HA powder and porous HA were characterized by wide angle X-ray diffraction, transmission electron microscopy(TEM), scanning electron microscopy (SEM), SEM in combination with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy. The experimental results show that HA powder synthesized by chemical precipitation is nanometer powder. Magnesium was ideal pore-creator for preparation of porous materials. The grain size of porous HA was sub-micron and MgO which existed in the grain boundary of HA as a second phase particles that played the roles of inhibiting the HA grain growth.

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Analytical Microscopic Analysis of Precipitates in Hastelloy Alloy C-276

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097922 ◽

1981 ◽

Vol 39 ◽

pp. 280-281

Author(s):

M. Raghavan ◽

B. J. Berkowitz ◽

J. C. Scanlon

Keyword(s):

Microscopic Analysis ◽

Scanning Transmission Electron Microscope ◽

Second Phase ◽

Precipitation Reaction ◽

X Ray Diffraction ◽

Corrosion Properties ◽

X Ray ◽

Transmission Electron ◽

Second Phase Particles ◽

Scanning Transmission

The present investigation was conducted to characterize the second phase particles in Hastelloy C-276 using an analytical Scanning Transmission Electron Microscope in order to understand their effect on the mechanical and Stress Corrosion properties of the alloy. Investigation in our 1aboratoryO) and previous published reports(2-4) have identified two types of precipitation reactions in this alloy. At temperatures in the range of 300-650°C, the alloy precipitates an ordered phase of the type Ni2(Cr, Mo)(1,2). This precipitation reaction is homogeneous with no preferential precipitation at the grain boundaries or twin boundaries. At temperatures above 650°C, several precipitate phases were observed to nucleate heterogeneously at boundaries and using X-ray diffraction techniques, the precipitates were previously identified as the μ, M6C and P phases(3-4). The present investigation was carried out to determine the composition of these second phase particles and this article describes the characterization of these precipitates using X-ray microanalysis and microdiffraction techniques.

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In-Situ MMC Production through VXBY Intermetallics Formation in an Al Matrix

Advanced Composites Letters ◽

10.1177/096369350301200102 ◽

2003 ◽

Vol 12 (1) ◽

pp. 096369350301200

Author(s):

C. Polyzos ◽

S. Skolianos ◽

H. Lefakis ◽

D.N. Tsipas

Keyword(s):

Aluminum Matrix ◽

Xrd Analysis ◽

Synthesis Temperature ◽

Second Phase ◽

X Ray Diffraction ◽

X Ray ◽

Second Phase Particles ◽

Stirring Time ◽

Al Matrix

The production of in-situ MMC's (Metal Matrix Composite) of an aluminum matrix with VxBy intermetallic compounds as the reinforcing phase has been investigated. The approach is modelled after that of Al-Ti-B alloys and salts added to an Al matrix to produce in-situ grain-refining TiB2. In the present work, V was used instead of Ti in an effort to investigate the possibility of an in-situ synthesis of a new, alternative, B-V reinforcing compound. Al, Al-V4.5wt% and Al-B5.5wt% alloys and a B-salt (KBF4) were used as starting materials. The synthesis temperature, the stirring time and the reaction holding time (RHT) were 1000°C, 5 min and 5 or 10 min respectively. The microstructure of the resulted MMC's consisted of second-phase particles, ranging in size between 1 and 10 μm, dispersed within an Al matrix. The second phase particles were identified by X-ray diffraction (XRD) analysis as VB2 and VB.

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Research on a New Type Grain Refiner Refining α-Al by Adding Molten State and Diluted Al-Ti-B-RE Master Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.535-537.915 ◽

2012 ◽

Vol 535-537 ◽

pp. 915-918

Author(s):

Zheng Jun Wang

Keyword(s):

Master Alloy ◽

Second Phase ◽

Grain Refining ◽

X Ray Diffraction ◽

Grain Refiner ◽

X Ray ◽

Second Phase Particles ◽

Refining Performance ◽

New Type ◽

The Cost

Al-Ti-B-RE master alloy was prepared by casting of pure Ti. To improve the quality and reduce the cost of α- Al, the Al-Ti-B-RE master alloy was added to α-Al in molten and diluted state. The refining method had the advantages of shorter contact time and better refining effect. The array of the second phase particles was separated and the nucleating rate was greatly increased. Analysis and comparison of the refining effects were by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy (OM).The refining experiment showed that the molten and diluted state Al-Ti-B-RE by oneself had better grain refining performance and had obvious advantages over Al-Ti-B in domestic.

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Deconvolution of morphological texture from crystallographic texture data

Journal of Applied Crystallography ◽

10.1107/s0021889802004168 ◽

2002 ◽

Vol 35 (3) ◽

pp. 327-337 ◽

Cited By ~ 3

Author(s):

Gijs Langelaan ◽

Laurent Delannay ◽

Ignaas Verpoest ◽

Paul Van Houtte

Keyword(s):

Crystallographic Texture ◽

316L Stainless Steel ◽

Experimental System ◽

Orientation Distribution ◽

Second Phase ◽

X Ray Diffraction ◽

X Ray ◽

Measurement Volume ◽

Second Phase Particles ◽

Weave Pattern

The physical properties of composite materials reinforced with fibres usually depend significantly on the orientation distribution of these fibres. The goal of this study is to develop a technique to measure the orientation distribution of second-phase particles which in themselves have a strong crystallographic texture. This permits the well known methods of pole-figure measurements to be used and the deconvolution of the `morphological texture function' from these data. In the current paper, the deconvolution procedure is presented and validated by simulations. Finally, the procedure is applied to an experimental system, which further confirms the validity of the approach. The simulations convoluted a morphological texture function with a crystallographic texture using a discrete representation of the orientation distribution function (ODF). After the convolution, the resulting ODF was converted to a series-expansion representation, which then permitted the deconvolution by an independent method. The results of the deconvolution return the original MTF, hence validating the procedure derived. The experimental system measured the crystallographic texture of 316L stainless-steel yarns woven into a fabric. The crystallographic texture obtained from straight yarns was used as the reference texture. The X-ray diffraction measurements reveal the weave pattern but with some ghosting errors. These are attributed to an insufficient measurement volume, which could be overcome by using radiation with a greater penetration, such as neutrons.

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The Effect of Cerium on Superplasticity of AL-6CU-0.35 MG-0.2ZR Alloy

MRS Proceedings ◽

10.1557/proc-196-283 ◽

1990 ◽

Vol 196 ◽

Author(s):

Wang Jingtao ◽

Wu Qingling ◽

Cul Jianzhong ◽

Zhou Haitao

Keyword(s):

Growth Rate ◽

Superplastic Deformation ◽

Second Phase ◽

X Ray Diffraction ◽

Rich Phase ◽

X Ray ◽

Microstructure Observation ◽

Second Phase Particles ◽

Superplastic Elongation ◽

Static Annealing

ABSTRACTThe effect of Cerium addition on the superplasticity of Al-6Cu-0.35Mg-O.2Zr alloy is investigated. The superplastic elongation of the alloy is increased from 450% to 500–700% by the addition of 0.5wt% Cerium, with some decrease in superplastic tensile resistance, when the alloy is deformed at 789K(516°C) with a strain rate of 8.33×10−4S−1. Microstructure observation shows that the addition of Cerium decreases the grain growth rate both in static annealing and during superplastic deformation. This is considered to be the result of the enhanced pinning of fine Zirconium-rich precipitates and the additional pinning of Cerium-rich phase particles. TEM and X-ray diffraction analysis show that Cerium in the alloy forms Cerium-rich phases (AlgCu4Ce and Al4CuCe), and these phase particles join in the pinning of second phase particles on grain boundary, stablizing the microstructure. The addition of Cerium also affects the distribution of Zirconium and Zirconium Aluminide in the alloy.

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Redistribution of Second Phase Particles in Surface Layers of Deformed Roll

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1013.158 ◽

2014 ◽

Vol 1013 ◽

pp. 158-165

Author(s):

Eduard Kozlov ◽

Mazhyn Skakov ◽

Gulzhaz Uazyrkhanova ◽

Natal'ya Popova

Keyword(s):

Volume Fraction ◽

Second Phase ◽

Structural Components ◽

Roll Surface ◽

X Ray Diffraction ◽

Surface Layers ◽

Near Surface ◽

X Ray ◽

Carbide Phases ◽

Second Phase Particles

Using optical and electron microscopy and also X-ray diffraction laws were investigated of carbide phases particles redistribution in the roll near-surface layers (at surface and at distance of 0.5 mm, 2 mm from surface) made of 30CrMnSiА steel during hot deformation. There are located at borders and joints of isotropic and anisotropic fragments and also inside these fragments. Shows the dependence of carbide phases volume fraction (cementite and special carbides). There are located in different structural components and different locations of the roll surface layer. Shows a relationship carbides with dislocation substructure. Shows a gradient character in the laws of carbide phases distribution as they approach the roll surface.

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Analytical Electron Microscopy Study of Second-Phase Particles in 7075 and 7475 Aluminum Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118618 ◽

1985 ◽

Vol 43 ◽

pp. 348-349

Author(s):

M. Raghavan ◽

J. Y. Koo ◽

J. W. Steeds ◽

B. K. Park

Keyword(s):

Aluminum Alloys ◽

Silicon Oxide ◽

Analytical Electron Microscopy ◽

Microscopy Study ◽

Electron Microscopy Study ◽

Partial Substitution ◽

Second Phase ◽

X Ray ◽

Second Phase Particles ◽

Almost All

X-ray microanalysis and Convergent Beam Electron Diffraction (CBD) studies were conducted to characterize the second phase particles in two commercial aluminum alloys -- 7075 and 7475. The second phase particles studied were large (approximately 2-5μm) constituent phases and relatively fine ( ∼ 0.05-1μn) dispersoid particles, Figures 1A and B. Based on the crystal structure and chemical composition analyses, the constituent phases found in these alloys were identified to be Al7Cu2Fe, (Al,Cu)6(Fe,Cu), α-Al12Fe3Si, Mg2Si, amorphous silicon oxide and the modified 6Fe compounds, in decreasing order of abundance. The results of quantitative X-ray microanalysis of all the constituent phases are listed in Table I. The data show that, in almost all the phases, partial substitution of alloying elements occurred resulting in small deviations from the published stoichiometric compositions of the binary and ternary compounds.

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Nanostructured TiO2-Based Composites for Light Absorption

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.975.207 ◽

2014 ◽

Vol 975 ◽

pp. 207-212

Author(s):

Dayse I. dos Santos ◽

Olayr Modesto Jr. ◽

Luis Vicente A. Scalvi ◽

Americo S. Tabata

Keyword(s):

Metal Oxide ◽

Light Absorption ◽

Structural Characteristics ◽

Sol Gel ◽

Second Phase ◽

X Ray Diffraction ◽

Two Phase ◽

X Ray ◽

Oxide Powders

Metal oxide nanocomposites were prepared by two different routes: polyol and sol-gel. Characterization by X ray diffraction showed that the first process produces directly a two-phase material, while the sol-gel powder never showed second phase below 600°C. Light spectroscopy of the treated powders indicated similarities for the processed materials. Although the overall material compositions are about the same, different structural characteristics are found for each processing. With the exception of Ti-Zn materials, all the double metal oxide powders showed higher absorbance than either TiO2 powder.

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X-ray diffraction and Raman study of DL-alanine at high pressure: revision of phase transitions

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768112028972 ◽

2012 ◽

Vol 68 (4) ◽

pp. 412-423 ◽

Cited By ~ 24

Author(s):

Nikolay A. Tumanov ◽

Elena V. Boldyreva

Keyword(s):

Phase Transition ◽

Phase Transitions ◽

Structural Phase ◽

Group Symmetry ◽

Second Phase ◽

Structural Phase Transitions ◽

X Ray Diffraction ◽

X Ray ◽

Cell Parameters ◽

Raman Study

The effect of pressure on DL-alanine has been studied by X-ray powder diffraction (up to 8.3 GPa), single-crystal X-ray diffraction and Raman spectroscopy (up to ∼ 6 GPa). No structural phase transitions have been observed. At ∼ 1.5–2 GPa, cell parameters b and c become accidentally equal to each other, but the space-group symmetry does not change. There is no phase transition between 1.7 and 2.3 GPa, contrary to what has been reported earlier [Belo et al. (2010). Vibr. Spectrosc. 54, 107–111]. The presence of the second phase transition, which was claimed to appear within the pressure range from 6.0 to 7.3 GPa (Belo et al., 2010), is also argued. The changes in the Raman spectra have been shown to be continuous in all the pressure ranges studied.

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