Nanocrystallization and Dissolution of Immiscible Powder Alloys Using High Pressure Torsion

2010 ◽  
Vol 667-669 ◽  
pp. 151-156
Author(s):  
Susi Kahofer ◽  
Michael Zehetbauer ◽  
Herbert Danninger ◽  
Erhard Schafler ◽  
Michael Kerber ◽  
...  
Keyword(s):  
Room Temperature ◽  
Vickers Microhardness ◽  
High Pressure Torsion ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
X Ray ◽  
Grain Sizes ◽  
Powder Alloys ◽  
Microhardness Data ◽  
Different Strains

Precompacts out of immiscible systems CuCr (75/25 wt%) and WCu (80/20 wt%), respectively, were made by pressing mixed powders and sintering. By applying different strains and hydrostatic pressures of HPT at room temperature, disc-shaped samples with a diameter of 8 mm were produced. They were investigated by Light Microscopy, Scanning-Electron Microscopy using Back-Scattered Electrons, and X-ray Line Profile Analysis. In addition, Vickers microhardness data were collected. Both systems showed the highest microhardness at a shear strain of about γ = 170. The density (for the case of Cu25Cr) of the consolidated material could be increased to the theoretical value. Microhardness and grain sizes were studied individually for each of the phases, too.

Structural, hardness and tribological behavior of TiAlNO coatings prepared by sputtering

2016 ◽  
Vol 1817 ◽  
Author(s):  
L. García González ◽  
S. R. Vásquez García ◽  
L. Zamora Peredo ◽  
A. López Velázquez ◽  
L. Domratcheva Lvova ◽  
...  
Keyword(s):  
Vickers Microhardness ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Nitrogen Flow ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes ◽  
Maximum Value ◽  
Phase Crystal ◽  
Steel Substrates

ABSTRACTAluminum titanium oxynitride (TiAlNO) coatings were deposited on 316 steel substrates by the sputtering technique, varying the nitrogen flow from 2.5, 5, 7.5 to 10 sccm, and maintaining constant at 12 sccm the flow argon gas. We used targets of titanium and alumina with 99.995% purity. The hardness and tribological analyses were determined by Vickers microhardness and tribology (tribometer pin-disc), respectively. The results show that the coating with a nitrogen flow of 10 sccm had the lowest volumetric wear (2.047738693 mm3) and the maximum value of hardness (11.2 GPa). Analysis of X-ray diffraction evidenced the presence of three crystalline phases: Ti2N, Al2O3 and TiO2. It can be observed that by increasing the nitrogen flow, the portion of semi-Ti2N phase increases, Al2O3 decreases and TiO2 remains almost constant, and also producing a change in crystallographic orientation with reference to the Ti2N phase. Crystal grain sizes were estimated by X-ray diffraction Fourier line profile analysis using Warren–Averbach method. This analysis showed a grain size between 5 and 15 nm. Raman spectroscopy results show the presence of the TiO2 phase which corroborated the X-ray diffraction results.

scholarly journals In-Situ Synchrotron Profile Analysis after High-Pressure Torsion Deformation

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 232 ◽  
Author(s):  
Michael Kerber ◽  
Florian Spieckermann ◽  
Roman Schuster ◽  
Bertalan Joni ◽  
Norbert Schell ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Pressure Torsion ◽  
Profile Analysis ◽  
Heating Process ◽  
Line Profile Analysis ◽  
X Ray ◽  
Pressure Release ◽  
Induced Defects

The presence of hydrostatic pressure is a general crucial characteristic of severe plastic deformation methods for reaching high strains and for introducing large quantities of lattice defects, which are necessary to establish new grain boundaries. Insights into the processes occurring during deformation and the influence of hydrostatic pressure are necessary to help better understand the SPD methods. A special experimental procedure was designed to simulate the hydrostatic pressure release: High pressure torsion (HPT)-deformed microstructure changes related to the release of hydrostatic pressure after the HPT deformation of copper and nickel were studied by freezing the sample before releasing the pressure. High-resolution in-situ X-ray diffraction of the heating process was performed using synchrotron radiation in order to apply X-ray line profile analysis to analyze the pressure release. The results on copper and nickel generally indicated the influence of hydrostatic pressure on the mobility and interaction of deformation-induced defects as well as the resulting microstructure.

scholarly journals The Effects of Severe Plastic Deformation and/or Thermal Treatment on the Mechanical Properties of Biodegradable Mg-Alloys

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1064 ◽  
Author(s):  
Andrea Ojdanic ◽  
Jelena Horky ◽  
Bernhard Mingler ◽  
Mattia Fanetti ◽  
Sandra Gardonio ◽  
...  
Keyword(s):  
Thermomechanical Processing ◽  
High Pressure Torsion ◽  
Profile Analysis ◽  
Tensile Tests ◽  
Line Profile Analysis ◽  
Thermal Treatments ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Quantitative Evaluations ◽  
Vacancy Concentrations

In this study, five MgZnCa alloys with low alloy content and high biocorrosion resistance were investigated during thermomechanical processing. As documented by microhardness and tensile tests, high pressure torsion (HPT)-processing and subsequent heat treatments led to strength increases of up to 250%; as much as about 1/3 of this increase was due to the heat treatment. Microstructural analyses by electron microscopy revealed a significant density of precipitates, but estimates of the Orowan strength exhibited values much smaller than the strength increases observed. Calculations using Kirchner’s model of vacancy hardening, however, showed that vacancy concentrations of 10−⁵ could have accounted for the extensive hardening observed, at least when they formed vacancy agglomerates with sizes around 50–100 nm. While such an effect has been suggested for a selected Mg-alloy already in a previous paper of the authors, in this study the effect was substantiated by combined quantitative evaluations from differential scanning calorimetry and X-ray line profile analysis. Those exhibited vacancy concentrations of up to about 10−3 with a marked percentage being part of vacancy agglomerates, which has been confirmed by evaluations of defect specific activation migration enthalpies. The variations of Young’s modulus during HPT-processing and during the subsequent thermal treatments were small. Additionally, the corrosion rate did not markedly change compared to that of the homogenized state.

Microstructure of post-deformed ECAP-Ti investigated by Multiple X-Ray Line Profile Analysis

2006 ◽  
Vol 2006 (suppl_23_2006) ◽  
pp. 129-134 ◽  
Author(s):  
E. Schafler ◽  
K. Nyilas ◽  
S. Bernstorff ◽  
L. Zeipper ◽  
M. Zehetbauer ◽  
...  
Keyword(s):  
Line Profile ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
X Ray

scholarly journals X-ray line profile analysis in alakali-treated ramie fiber

2003 ◽  
Vol 60 (6) ◽  
pp. 919-922 ◽  
Author(s):  
K. P. Sao ◽  
B. K. Samantaray ◽  
S. Bhattacherjee
Keyword(s):  
Line Profile ◽  
Profile Analysis ◽  
Ramie Fiber ◽  
Line Profile Analysis ◽  
X Ray

scholarly journals Investigations on Microstructural and Layer Disorder Parameters of Na-Montmorillonite-Glycine Intercalation Compounds

2012 ◽  
Vol 60 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Adnan Hossain Khan ◽  
Parimal Bala ◽  
AFM Mustafizur Rahman ◽  
Mohammad Nurnabi
Keyword(s):  
Crystallite Size ◽  
Chain Length ◽  
Line Profile ◽  
Profile Analysis ◽  
Interlayer Spacing ◽  
Line Profile Analysis ◽  
X Ray ◽  
Microstructural Parameters ◽  
Silicate Layers ◽  
Layer Disorder

Glycine-Montmorillonite (Gly-MMT) composite has been synthesized through intercalation process using Na-Montmorillonite (Na- MMT) and glycine ethylester hydrochloride. Gly-MMT was employed for the synthesis of dipeptide (Gly-Gly-MMT). Microstructural parameters such as crystallite size, r.m.s. strain (<e2>1/2) and layer disorder parameters such as variation of interlayer spacing (g) and proportion of planes affected by such defects (?) of the samples have been calculated by X-ray line profile analysis. In comparison to Na-MMT the basal spacings (d001) of Gly-MMT and Gly-Gly-MMT were reduced by 2.4Å and 1.8Å respectively. The value of d001 of Gly-Gly-MMT (13.3 Å) suggests the monolayer orientation of dipeptide into interlayer spaces. It is also suggested that more homogeneity in the stacking of silicate layers is attained in Gly-Gly-MMT due to the increased chain length of the dipeptide and orientation in monolayer style.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10331Dhaka Univ. J. Sci. 60(1): 25-29, 2012 (January)

Characterization of Mn0.67Zn0.33Fe2O4 Nanoparticles Synthesized under Different pH

2017 ◽  
Vol 899 ◽  
pp. 48-53
Author(s):  
Rodrigo Uchida Ichikawa ◽  
Walter Kenji Yoshito ◽  
Margarida Juri Saeki ◽  
Willian C.A. Maranhão ◽  
Fátima Goulart ◽  
...  
Keyword(s):  
Profile Analysis ◽  
Rietveld Method ◽  
Spinel Phase ◽  
Sem Analysis ◽  
Line Profile Analysis ◽  
X Ray ◽  
Cell Parameters ◽  
Zn Ferrite ◽  
Crystallite Sizes ◽  
Co Precipitation

Nanostructured Mn-Zn ferrites were synthesized using co-precipitation in alkaline solution with different pH. The samples were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), thermal analysis (TG-DTA), dynamic light scattering (DLS) and scanning electron microscopy (SEM) techniques. Monophasic nanoparticles were formed when synthesized with pH 10.5. This sample was heat-treated and its XRD data was refined by the Rietveld method. Mean crystallite sizes and microstrains were determined from X-ray line profile analysis using Single-Line and Warren-Averbach methods, which revealed a mean crystallite size of approximately 10 nm and negligible microstrains. Zn content was estimated using refined cell parameters, giving a value of 33 at %, in accordance with XRF result. TG-DTA revealed that the incorporation of α-Fe2O3 occurs around 1130 °C and 1200 °C with recrystallization of the Mn-Zn ferrite spinel phase. DLS showed that mean particle size increase with temperature up to 1159 nm at 800 °C. SEM analysis showed the samples agglomerate and present similar morphology with negligible size changing when calcined between 280 °C and 800 °C. However, the sample calcined at 1200 °C presents larger agglomerates due to the sintering process.

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