Gradient residual strain and stress distributions in a high pressure torsion deformed iron disk revealed by high energy X-ray diffraction

2018 ◽  
Vol 146 ◽  
pp. 178-181 ◽  
Author(s):  
J. Todt ◽  
J. Keckes ◽  
G. Winter ◽  
P. Staron ◽  
A. Hohenwarter
Keyword(s):  
High Pressure ◽  
Residual Strain ◽  
High Pressure Torsion ◽  
High Energy ◽  
Stress Distributions ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Effect of the High-Pressure Torsion (HPT) and Subsequent Isothermal Annealing on the Phase Transformation in Biomedical Ti15Mo Alloy

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1194 ◽  
Author(s):  
Kristína Bartha ◽  
Josef Stráský ◽  
Anna Veverková ◽  
Pere Barriobero-Vila ◽  
František Lukáč ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Phase Evolution ◽  
High Energy ◽  
Phase Precipitation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solution Treated ◽  
Α Phase ◽  
Element Partitioning

Ti15Mo metastable beta Ti alloy was solution treated and subsequently deformed by high-pressure torsion (HPT). HPT-deformed and benchmark non-deformed solution-treated materials were annealed at 400 °C and 500 °C in order to investigate the effect of UFG microstructure on the α-phase precipitation. Phase evolution was examined using laboratory X-ray diffraction (XRD) and by high-energy synchrotron X-ray diffraction (HEXRD), which provided more accurate measurements. Microstructure was observed by scanning electron microscopy (SEM) and microhardness was measured for all conditions. HPT deformation was found to significantly enhance the α phase precipitation due the introduction of lattice defects such as dislocations or grain boundaries, which act as preferential nucleation sites. Moreover, in HPT-deformed material, α precipitates are small and equiaxed, contrary to the α lamellae in the non-deformed material. ω phase formation is suppressed due to massive α precipitation and consequent element partitioning. Despite that, HPT-deformed material after ageing exhibits the high microhardness exceeding 450 HV.

Control of Crystallographic Orientation and Grain Refinement in Bi2Te3-Based Thermoelectric Semiconductors by Applying High Pressure Torsion

2008 ◽  
Vol 584-586 ◽  
pp. 1006-1011 ◽  
Author(s):  
Maki Ashida ◽  
Takashi Hamachiyo ◽  
Kazuhiro Hasezaki ◽  
Hirotaka Matsunoshita ◽  
Masaaki Kai ◽  
...  
Keyword(s):  
High Pressure ◽  
Crystal Orientation ◽  
High Pressure Torsion ◽  
Crystallographic Structure ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Refined Microstructure ◽  
Vertical Bridgman ◽  
P Type

Prepared were p-type Bi2Te3-based thermoelectric semiconductors, having a grain-refined microstructure and a preferred orientation of anisotropic crystallographic structure. Disks with a nominal composition Bi0.5Sb1.5Te3.0 were cut from an ingot grown by the vertical Bridgman method (VBM) and deformed at 473 K under a pressure of 6.0 GPa by high pressure torsion (HPT). The crystal orientation was characterized with X-ray diffraction. The microstructures were characterized by using optical microscopy and scanning electron microscopy. It was found that the HPT disks had a fine and preferentially oriented grain compared to that of the VBM disks. Further, the power factor of the HPT disks was about twice as large as that of the VBM disks. These results indicate that HPT is effective for improving the thermoelectric properties of Bi2Te3-based thermoelectric semiconductors.

scholarly journals Influence of HPT and Accumulative High-Pressure Torsion on the Structure and Hv of a Zirconium Alloy

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 573
Author(s):  
Dmitry Gunderov ◽  
Andrey Stotskiy ◽  
Yuri Lebedev ◽  
Veta Mukaeva
Keyword(s):  
High Pressure ◽  
Zirconium Alloy ◽  
High Pressure Torsion ◽  
Ti Alloy ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ω Phase ◽  
First Time ◽  
Torsion Deformation

The authors previously used the accumulative high-pressure torsion (ACC HPT) method for the first time on steel 316, β-Ti alloy, and bulk metallic glass vit105. On low-alloyed alloys, in particular, the zirconium alloy Zr-1%Nb, the new method was not used. This alloy has a tendency to α → ω phase transformations at using simple HPT. When using ACC HPT, the α → ω transformation can be influenced to a greater extent. This article studies the sliding effect and accumulation of shear strain in Zr-1%Nb alloy at various stages of high-pressure torsion (HPT). The degree of shear deformation at different stages of HPT was estimated. The influence of various high-pressure torsion conditions on the micro-hardness and phase composition by X-ray diffraction (XRD) of Zr-1%Nb was analyzed. It is shown that at high-pressure torsion revolutions of n = 2, anvils and the specimen significantly slip, which is a result of material strengthening. It was found that despite sliding, regular high-pressure torsion resulted in the high strengthening of Zr-1%Nb alloy (micro-hardness more than doubled), and after high-pressure torsion n = 10, up to 97% of the high-pressure ω-phase was formed in it (as in papers of other researchers). Accumulative high-pressure torsion deformation leads to the strongest transformation of the Zr-1%Nb structure and Hv and, therefore, to a higher real strain of the material due to composition by upsetting and torsion in strain cycles.

Peculiarities in the Texture Formation of Intermetallic Compounds Deformed by High Pressure Torsion

2014 ◽  
Vol 1760 ◽  
Author(s):  
Christine Tränkner ◽  
Aurimas Pukenas ◽  
Jelena Horky ◽  
Michael Zehetbauer ◽  
Werner Skrotzki
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Electron Backscatter Diffraction ◽  
High Energy ◽  
X Ray ◽  
Local Texture ◽  
Large Rotations ◽  
Electron Backscatter ◽  
Shear Strains ◽  
Backscatter Diffraction

ABSTRACTNiAl, YCu and TiAl polycrystals with B2 and L10 structure, respectively, have been deformed by high pressure torsion (HPT) at temperatures between 20°C and 500°C at a hydrostatic pressure of 8 GPa to high shear strains. Local texture measurements were done by diffraction of high-energy synchrotron radiation and X-ray microdiffraction. In addition, the microstructure was analyzed by electron backscatter diffraction (EBSD). Besides typical shear components an oblique cube component is observed with quite large rotations about the transverse direction. Based on the temperature dependence of this component as well as on microstructure investigations it is concluded that it is formed by discontinuous dynamic recrystallization. The influence of high pressure on recrystallization of intermetallics at low temperatures is discussed.

Analysis of high-energy x-ray diffraction data at high pressure: the case of vitreous As2O3at 32 GPa

2007 ◽  
Vol 19 (41) ◽  
pp. 415103 ◽  
Author(s):  
Q Mei ◽  
C J Benmore ◽  
E Soignard ◽  
S Amin ◽  
J L Yarger
Keyword(s):  
High Pressure ◽  
Diffraction Data ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray

On the calibration of high-energy X-ray diffraction setups. II. Assessing the rotation axis and residual strains

2014 ◽  
Vol 47 (5) ◽  
pp. 1585-1595 ◽  
Author(s):  
Andras Borbély ◽  
Loïc Renversade ◽  
Peter Kenesei
Keyword(s):  
Residual Strain ◽  
Rotation Axis ◽  
Strain Tensor ◽  
High Energy ◽  
Laboratory Frame ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Area Detector ◽  
Residual Strains

The calibration of high-energy X-ray diffraction setups using an area detector and a rotation axis is discussed. The characterization of the tilt and spatial distortions of an area detector was discussed in part one of this series [Borbély, Renversade, Kenesei & Wright (2014).J. Appl. Cryst.47, 1042–1053]. Part II links the detector frame to the laboratory frame comprising an additional rotation axis and introduces a general diffractometer equation accounting for all sources of misalignment. Additionally, an independent high-accuracy method for the evaluation of the crystallographic orientation and cell parameters of the undeformed reference crystal is presented. Setup misalignments are mainly described in terms of a residual strain tensor, considered as a quality label of the diffractometer. The method is exemplified using data sets acquired at beamlines ID11 (European Synchrotron Radiation Facility) and 1-ID (Advanced Photon Source) on Al and W single crystals, respectively. The results show that the residual strain tensor is mainly determined by the detector spatial distortion, and values as small as 1–2 × 10−4can be practically achieved.

Synchrotron X-ray diffraction observation of phase transformation during annealing of Si processed by high-pressure torsion

2021 ◽  
pp. 1-9
Author(s):  
Yoshifumi Ikoma ◽  
Terumasa Yamasaki ◽  
Takahiro Masuda ◽  
Yoshinori Tange ◽  
Yuji Higo ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
High Pressure Torsion ◽  
X Ray Diffraction ◽  
X Ray

Hydrogen Storage, Microstructure and Mechanical Properties of Strained Mg65Ni20Cu5Y10 Metallic Glass

2012 ◽  
Vol 729 ◽  
pp. 74-79
Author(s):  
Ádám Révész ◽  
Ágnes Kis-Tóth ◽  
Péter Szommer ◽  
Tony Spassov
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Shear Deformation ◽  
High Pressure Torsion ◽  
Hydrogen Uptake ◽  
X Ray Diffraction ◽  
X Ray ◽  
Melt Spun ◽  
Lower Temperature ◽  
Scanning Electron

Melt-spun amorphous Mg65Ni20Cu5Y10metallic glass compacts were subjected to severe shear deformation by high-pressure torsion. High-resolution X-ray diffraction analysis and scanning electron microscopy revealed that high-pressure torsion resulted in a deformation dependent microstructure. Nanoindentation measurements indicated that the heavy shear deformation yields an increase in hardness. High-pressure calorimetry measurements revealed that hydrogen uptake in the fully amorphous alloy occurs at a significantly lower temperature compared to the fully crystallized state, while the amount of absorbed hydrogen increased considerably after shear strain due to the formation of Mg2Ni crystals.

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