scholarly journals Microstructural Evolution and Tensile Testing of a Bi–Sn (57/43) Alloy Processed by Tube High-Pressure Shearing

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1229
Author(s):  
Chuan-Ting Wang ◽  
Zheng Li ◽  
Yong He ◽  
Jing-Tao Wang ◽  
Terence G. Langdon
Keyword(s):  
High Pressure ◽  
Tensile Testing ◽  
Lamellar Structure ◽  
Room Temperature ◽  
Eutectic Structure ◽  
Annealing Behavior ◽  
High Elongation ◽  
Temperature Shear ◽  
Superplastic Properties ◽  
Subsequent Storage

Tube high-pressure shearing (t-HPS) processing was performed on a eutectic Bi–Sn (57/43) alloy for 0.25, 1, 5 and 20 turns. The selected samples were stored at room temperature for up to 56 days to examine the strain weakening and self-annealing behavior of the alloy. The results showed that t-HPS processing gradually refined the microstructure and led to decreasing of microhardness, but microhardness increased slowly during the subsequent storage at room temperature. Shear localization of the eutectic structure during t-HPS processing was observed as large amounts of narrow dense lamellar zones were visible in the deformed microstructures. The Bi–Sn (57/43) alloy processed by t-HPS exhibited significantly enhanced superplastic properties with elongations up to >1800% in a sample after t-HPS processing for 20 turns. This high elongation is attributed to the breaking of the lamellar structure and the very small grain size.

Microtextural Changes and Superplasticity in an Al-7075 Alloy Processed by High-Pressure Torsion

2016 ◽  
Vol 838-839 ◽  
pp. 445-450 ◽  
Author(s):  
Aicha Loucif ◽  
Yi Huang ◽  
Anne Laure Helbert ◽  
Thierry Baudin ◽  
Shima Sabbaghianrad ◽  
...  
Keyword(s):  
High Pressure ◽  
Tensile Testing ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pole Figures ◽  
Al 7075 ◽  
7075 Alloy ◽  
Superplastic Properties

The influence of High-Pressure Torsion (HPT) on texture and superplasticity in an Al-7075 was studied using X-ray diffraction and tensile testing. The alloy was processed by HPT at room temperature under a pressure of 6.0 GPA up to a maximum of 20 turns. The pole figures were measured at mid-radius of the disks after 1, 5, 10 and 20 turns. The results show the presence of a typical torsion texture during HPT, in particular, the C{001}<110> component was found to develop preferentially. With increasing deformation, the A {111}<110> and the C components are reinforced after 5 turns and the texture tends to be random with the presence of a fibre texture near the center. Moreover, the fraction of C components tends to gradually decrease and a fairly isotropic microtexture is apparent after 20 turns. Tensile testing showed the development of excellent superplastic properties in this alloy with elongations up to ~700% when testing at a temperature of 623 K.

Effect of Different Initial Lamellar Plate Thicknesses on Grain Refinement and Superplastic Behaviour in HPT-Processed Ti-6Al-4V Alloy

2018 ◽  
Vol 385 ◽  
pp. 182-188
Author(s):  
Yi Huang ◽  
Jessica Muzy ◽  
Piotr Bazarnik ◽  
Małgorzata Lewandowska ◽  
Terence G. Langdon
Keyword(s):  
High Pressure ◽  
Lamellar Structure ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Phase Transformation Temperature ◽  
Air Cooling ◽  
Microstructure Development ◽  
Superplastic Behaviour ◽  
Β Phase ◽  
Heat Treated

Ti-6Al-4V alloy was heated to above the β phase transformation temperature with two different cooling speeds: air cooling and furnace cooling, in order to generate a full thin lamellar structure and a fully coarse lamellar structure, respectively. Then the alloy in two heat-treated conditions was processed at room temperature up to 10 turns by high-pressure torsion (HPT) processing. Investigations were carried out to study the effect of the different initial lamellar plate thicknesses on the microstructure development during HPT processing, and the corresponding superplastic behaviour at the selected low testing temperatures of 773 - 923 K.

Application of High Pressure Torsion to Bulk Samples

2006 ◽  
Vol 503-504 ◽  
pp. 391-398 ◽  
Author(s):  
Genki Sakai ◽  
Katsuaki Nakamura ◽  
Z. Horita ◽  
Terence G. Langdon
Keyword(s):  
High Pressure ◽  
Tensile Testing ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Initial Strain Rate ◽  
Thin Disk ◽  
Metallic Materials ◽  
Grain Sizes ◽  
Angular Pressing ◽  
Cylindrical Samples

High pressure torsion (HPT) is a well-known procedure to impart severe plastic deformation (SPD) into metallic materials. It was reported that HPT produces grain sizes finer than those using other SPD processes such as equal-channel angular pressing (ECAP). However, the application of HPT has been restricted to thin disk samples. In this study, an HPT process was developed for use with bulk samples. This process is designated as Bulk-HPT for comparison with conventional Disk-HPT. Cylindrical samples of an Al-3%Mg-0.2%Sc alloy having dimensions of 10 mm in diameter and 8.6 mm in height were prepared for Bulk-HPT. The samples were strained under a pressure of 1 GPa for 2 turns at room temperature. Microstructural observations revealed that the samples contained regions having a grain size of ~130 nm. Tensile testing showed a superplastic ductility ~480 % at 673 K with an initial strain rate of 3.3x10-2 s-1.

Effect of high pressure processing (HPP) on spore preparation of probiotic Bacillus coagulans LBSC [DSM 17654]

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pratik Bagkar ◽  
Anil Kumar Gupta ◽  
Chiranjit Maity
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
Reference Strain ◽  
Bacillus Coagulans ◽  
Storage Conditions ◽  
High Pressure Processing ◽  
Processed Food ◽  
Modern Age ◽  
Subsequent Storage ◽  
Temperature Storage

Abstract High pressure processing (HPP) has become a mainstream technology for modern age food processing. HPP conditions are detrimental to inherent microbial flora, including food pathogens. A probiotic intended for supplementation in a high-pressured processed food should therefore be stable to processing and subsequent storage conditions. The present study reports the viability of Bacillus coagulans LBSC [DSM 17654] spores at high hydrostatic pressures (HHP, 450 and 550 MPa) processing. B. coagulans LBSC spores were viable under both pressure condition at pH 2.60, 5.00, 7.00, and 8.25. Similar HPP conditions completely inactivated a reference strain Escherichia coli ATCC 25922. The HPP treated B. coagulans LBSC spore preparation showed no reduction in the viability on room temperature storage for a duration of six months. Results demonstrated the resilience of probiotic B. coagulans LBSC spores under HPP treatment, suggesting its potential incorporation in a range of functional foods and beverages.

Evaluation of Variation Mechanical Properties in AZ91D Magnesium Alloy Processed by Extrusion and ECAP

2013 ◽  
Vol 753-755 ◽  
pp. 191-194
Author(s):  
Bao Zhi Xie
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Tensile Testing ◽  
Room Temperature ◽  
Initial Strain Rate ◽  
Maximum Elongation ◽  
Az91d Magnesium Alloy ◽  
Superplastic Properties

Microstructure evolution and mechanical properties of AZ91D magnesium alloys which was processed by EX-ECAP at 473K were investigated in this study. Microstructural inspection showed that the EX-ECAP was effective in refine grain size of the alloy. Tensile testing at room temperature showed that the ductility, strength and hardness of the alloy have been significantly increased by EX-ECAP. The alloy exhibited excellent superplastic properties in the form of the maximum elongation of ~218% at 473K using an initial strain rate of 3×10-4s-1.

Influence of Equal-Channel Angular Pressing on the Superplastic Properties of Commercial Aluminum Alloys

1999 ◽  
Vol 601 ◽  
Author(s):  
Sungwon Lee ◽  
Terence G. Langdon
Keyword(s):  
Aluminum Alloys ◽  
Strain Rate ◽  
Tensile Testing ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
High Strain ◽  
Optimum Temperature ◽  
Angular Pressing ◽  
Superplastic Properties ◽  
Al 2024

AbstractEqual-channel angular (ECA) pressing was used to refine the microstructure in two commercial aluminum alloys, Al-2024 and the Supral-100 Al-2004 alloy. The ECA pressing was conducted at room temperature and at elevated temperatures for both alloys using several different processing routes. Tensile testing was carried out at elevated temperatures on both pressed and unpressed samples of each alloy in order to evaluate the effect of the pressing. This paper describes the influence of the ECA pressing on the subsequent mechanical properties of these two alloys. For both alloys, it is shown that the optimum superplastic conditions are influenced by the ECA pressing, and in practice there tends to be a decrease in the optimum temperature for superplasticity and a corresponding increase in the optimum strain rate. In addition, there was evidence for high strain rate superplasticity (HSR SP) in both alloys after the ECA pressing procedure.

High-pressure freezing and freeze substitution of teliospores of the rust fungus Gymnosporangium clavipes

1990 ◽  
Vol 48 (3) ◽  
pp. 692-693
Author(s):  
Robert W. Roberson
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
Pathogenic Fungus ◽  
Rust Fungus ◽  
Freeze Substitution ◽  
Ice Crystals ◽  
High Pressure Freezing ◽  
Thin Walled Structures ◽  
Cytological Changes ◽  
Dextran Solution

The use of cryo-techniques for the preparation of biological specimens in electron microscopy has led to superior preservation of ultrastructural detail. Although these techniques have obvious advantages, a critical limitation is that only 10-40 μm thick cells and tissue layers can be frozen without the formation of distorting ice crystals. However, thicker samples (600 μm) may be frozen well by rapid freezing under high-pressure (2,100 bar). To date, most work using cryo-techniques on fungi have been confined to examining small, thin-walled structures. High-pressure freezing and freeze substitution are used here to analysis pre-germination stages of specialized, sexual spores (teliospores) of the plant pathogenic fungus Gymnosporangium clavipes C & P.Dormant teliospores were incubated in drops of water at room temperature (25°C) to break dormancy and stimulate germination. Spores were collected at approximately 30 min intervals after hydration so that early cytological changes associated with spore germination could be monitored. Prior to high-pressure freezing, the samples were incubated for 5-10 min in a 20% dextran solution for added cryoprotection during freezing. Forty to 50 spores were placed in specimen cups and holders and immediately frozen at high pressure using the Balzers HPM 010 apparatus.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

RMI 6Al-ELI

Alloy Digest ◽  
1988 ◽  
Vol 37 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Pressure ◽  
Room Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
Age Hardening ◽  
Bend Strength ◽  
Annealed Condition ◽  
Room Temperature Yield Strength ◽  
Alpha Beta

Abstract RMI 6A1-4V ELI is an alpha-beta type of titanium-base alloy that can be strengthened by age hardening. In the mill-annealed condition it has a guaranteed minimum room-temperature yield strength of 120,000 psi and can be increased to as much as 160,000 psi by solution treating and aging. This alloy may be used for high-pressure cryogenic vessels down to 320 F. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-89. Producer or source: RMI Company.

scholarly journals High-Pressure Spectroscopy Study of Zn(IO3)2 Using Far-Infrared Synchrotron Radiation

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Akun Liang ◽  
Robin Turnbull ◽  
Enrico Bandiello ◽  
Ibraheem Yousef ◽  
Catalin Popescu ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Transitions ◽  
Synchrotron Radiation ◽  
Infrared Radiation ◽  
Room Temperature ◽  
Far Infrared ◽  
Low Pressure ◽  
Pressure Response ◽  
Spectroscopy Study ◽  
Far Infrared Radiation

We report the first high-pressure spectroscopy study on Zn(IO3)2 using synchrotron far-infrared radiation. Spectroscopy was conducted up to pressures of 17 GPa at room temperature. Twenty-five phonons were identified below 600 cm−1 for the initial monoclinic low-pressure polymorph of Zn(IO3)2. The pressure response of the modes with wavenumbers above 150 cm−1 has been characterized, with modes exhibiting non-linear responses and frequency discontinuities that have been proposed to be related to the existence of phase transitions. Analysis of the high-pressure spectra acquired on compression indicates that Zn(IO3)2 undergoes subtle phase transitions around 3 and 8 GPa, followed by a more drastic transition around 13 GPa.

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