Effect of Low Temperature Rolling on Microstructure and Properties of ECAE Processed Copper

Fourth Pass ◽

Initial Processing ◽

The changes in the tensile properties, in relation to the phenomenon of shear banding are investigated in copper, rolled at liquid nitrogen temperature and then recrystallized, after initial processing by Equal-Channel Angular Extrusion (ECAE) at room temperature. Increases in ductility and strength up to the fourth pass of ECAE processing were noted, then a decrease of both properties was observed. The decrease was accompanied by twinning and shear banding. In rolled samples, pre-cooled down to the temperature of liquid nitrogen and initially recrystallized, the twinning and shear banding mechanisms were the most probable mechanisms responsible for lowering the mechanical properties.

Effect of Rolling Temperature on Microstructure and Mechanical Properties of Cryorolled Al-Mg-Si Alloy Reinforced with 3wt% TiB2 In Situ Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.584.556 ◽

2012 ◽

Vol 584 ◽

pp. 556-560 ◽

Cited By ~ 11

Author(s):

B. Gopi ◽

N. Naga Krishna ◽

K. Sivaprasad ◽

K. Venkateswarlu

Keyword(s):

Mechanical Properties ◽

Liquid Nitrogen ◽

Room Temperature ◽

True Strain ◽

Tensile Tests ◽

Rolling Temperature ◽

Rolled Sample ◽

Peak Broadening

The present work investigates the effect of rolling temperature on the mechanical properties and microstructural evolution of an Al-Mg-Si alloy with 3wt% TiB2 in-situ composite that was fabricated by stir casting route. The composite was rolled to a true strain of ≈0.7 at three different temperatures viz; room temperature (RT), liquid propanol (LP) and liquid nitrogen (LN) temperatures. Tensile tests revealed that the samples rolled at liquid nitrogen temperature exhibited improved properties compared to the samples rolled at other two temperatures. A tensile strength and ductility of 291 MPa and 8% respectively were exhibited by the liquid nitrogen rolled sample. The strength is observed to be ≈12% higher and ductility is ≈60% more when compared to the room temperature rolled sample. X ray diffraction peaks indicated that rolled samples exhibited considerable increase in peak broadening compared to the unrolled one, which is attributed to the increase of the lattice strain due to distortion and the decrease in grain size of the material. The enhanced mechanical properties of the liquid nitrogen rolled samples were attributed to the combined effect of grain refinement and accumulation of higher dislocation density.

Effect of low temperature rolling on mechanical properties and corrosion resistance of CrCoNi medium entropy alloy

Materials Research Express ◽

10.1088/2053-1591/ac45bc ◽

2021 ◽

Author(s):

Jinliang Chen ◽

Zhongxue Feng ◽

Jianhong Yi ◽

Jun Yang

Keyword(s):

Tensile Strength ◽

Corrosion Resistance ◽

Low Temperature ◽

Liquid Nitrogen ◽

Magnetic Levitation ◽

Rolling Direction ◽

304 Stainless Steel ◽

Mechanical Properties And Corrosion ◽

Abstract Abstract: For the casted CrCoNi medium entropy alloy melted by magnetic levitation, the deformation was carried out in 4 passes under the condition of liquid nitrogen temperature (-196°C), the total reduction was 50%,The microstructure and properties were analyzed after liquid nitrogen low temperature rolled. The experimental data showed that the phase structure of the alloy was not changed under the low-temperature rolling. The grains, crushed and refined, were elongated along the rolling direction. With the increasing of passes and reduction, the tensile strength increased from 585 MPa to 1359 MPa, while the elongation decreased from 37.8% to 5.9%. work With the increasing of work hardening,the tensile strength of the CrCoNi medium entropy alloy gradually increased, while the plasticity dramatic decreased. At the same time,the corrosion resistance of the CrCoNi medium entropy alloy was improved by low temperature cold rolled. The corrosion resistance of as-cast and rolled CrCoNi was much better than 304 stainless steel.

Microstructure Evolution of Mg-2Y-0.6Nd-0.6Zr Alloy Rolled at Room and Liquid Nitrogen Temperature

10.21203/rs.3.rs-596954/v1 ◽

2021 ◽

Author(s):

Yun Tan ◽

Wei Li ◽

Aiwen Li ◽

Xiaofang Shi

Keyword(s):

Liquid Nitrogen ◽

Microstructure Evolution ◽

Room Temperature ◽

Extrusion Direction ◽

Processed Material ◽

Cold Rolled ◽

Room Temperature Rolling ◽

Lower Temperature ◽

Abstract The microstructure evolution, texture, mechanical behavior and twin deformation of the ECAPed Mg-2Y-0.6Nd-0.6Zr alloy at liquid nitrogen temperature were investigated by rolling samples. The ECAP processed material appeared the texture of 45 ° to the extrusion direction and its yield strength reached 93.6 MPa. The results showed that cryorolling encourages twinning in Mg-2Y-0.6Nd-0.6Zr alloy, enhancing the tensile strength and texture. Activation of {10-12} twinning during rolling was found to be more pronounced in the cryorolled samples than in the cold rolled samples owing to a lower temperature. As a result, the cryorolled samples had more twins than and cold rolled ones, the proportion of twin areas of room temperature rolling and ultra-low temperature rolling were: 2.445% and 4.234%.

Microstructure and properties evolution of Mg–2Y–0.6Nd–0.6Zr alloy rolled at room and liquid nitrogen temperature

Scientific Reports ◽

10.1038/s41598-021-99706-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yun Tan ◽

Wei Li ◽

Aiwen Li ◽

Xiaofang Shi

Keyword(s):

Tensile Strength ◽

Liquid Nitrogen ◽

Room Temperature ◽

Extrusion Direction ◽

Processed Material ◽

Cold Rolled ◽

Room Temperature Rolling ◽

Lower Temperature ◽

AbstractThe microstructure evolution, texture, mechanical behavior and twin deformation of the ECAPed Mg–2Y–0.6Nd–0.6Zr alloy at room and liquid nitrogen temperature were investigated by rolling samples. The ECAP processed material appeared the texture of 45° to the extrusion direction and its yield strength reached 93.6 MPa. The results showed that cryorolling encourages twinning in Mg–2Y–0.6Nd–0.6Zr alloy, enhancing the tensile strength and texture. Activation of {10–12} twinning during rolling was found to be more pronounced in the cryorolled samples than in the cold rolled samples owing to a lower temperature. As a result, the cryorolled samples had more twins than and cold rolled ones, the proportion of twin areas of room temperature rolling and ultra-low temperature rolling were: 2.45% and 4.23%.

Cryogenic Interlaminar Properties of PBO Fiber/Epoxy Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.391-392.1445 ◽

2011 ◽

Vol 391-392 ◽

pp. 1445-1449

Author(s):

Chun Hua Zhang ◽

Shi Lin Luan ◽

Xiu Song Qian ◽

Bao Hua Sun ◽

Wen Sheng Zhang

Keyword(s):

Liquid Nitrogen ◽

Room Temperature ◽

Epoxy Composites ◽

Bending Test ◽

Test Results ◽

Sem Images ◽

Three Point Bending ◽

Pbo Fiber ◽

Interlaminar Shear

The influences of low temperature on the interlaminar properties for PBO fiber/epoxy composites have been studied at liquid nitrogen temperature (77 K) in terms of three point bending test. Results showed that the interlaminar shear strength at 77 K were significantly higher than those at room temperature (RT). For the analysis of the test results, the tensile behaviors of epoxy resin at both room temperature and liquid nitrogen temperature were investigated. The interface between fiber and matrix was observed using SEM images.

Low-temperature degradation resistance and plastic deformation of ATZ ceramics stabilized by CaO

Journal of Physics Conference Series ◽

10.1088/1742-6596/2103/1/012075 ◽

2021 ◽

Vol 2103 (1) ◽

pp. 012075

Author(s):

AA Dmitrievskiy ◽

DG Zhigacheva ◽

VM Vasyukov ◽

PN Ovchinnikov

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Plastic Deformation ◽

Compressive Strength ◽

Phase Composition ◽

Low Temperature ◽

Uniaxial Compression ◽

Calcium Oxide ◽

Tetragonal Phase ◽

Room Temperature

Abstract In this work, the phase composition (relative fractions of monoclinic m-ZrO2, tetragonal t-ZrO2, and cubic c-ZrO2 phases) and mechanical properties (hardness, fracture toughness, compressive strength) of alumina toughened zirconia (ATZ) ceramics, with an addition of silica were investigated. Calcium oxide was used as a stabilizer for the zirconia tetragonal phase. It was shown that CaO-ATZ+SiO2 ceramics demonstrate increased resistance to low-temperature degradation. The plasticity signs at room temperature were found due to the SiO2 addition to CaO-ATZ ceramics. A yield plateau appears in the uniaxial compression diagram at 5 mol. % SiO2 concentration. It is hypothesized that discovered plasticity is due to the increased t→m transformability.

Compressive Plasticity of Zr-Based Bulk Metallic Glass at Low Temperature

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.443-444.583 ◽

2012 ◽

Vol 443-444 ◽

pp. 583-586

Author(s):

Ya Juan Sun ◽

Ri Ga Wu ◽

Hong Jing Wang

Keyword(s):

Mechanical Properties ◽

Low Temperature ◽

Metallic Glass ◽

Bulk Metallic Glass ◽

Low Temperatures ◽

Room Temperature ◽

Shear Bands ◽

Strain Curve ◽

Testing Temperature ◽

Stress Strain Curve

The mechanical properties of a new Zr-based bulk metallic glass at low temperatures were investigated. The results indicate that the fracture strength increases significantly (4.9%) and the global plasticity increases somewhat when testing temperature is lowered to 123K. The stress-strain curve of the sample deformed exhibits more serrations and smaller stress drop due to formation of more shear bands at low temperature than at room temperature.

Research on DC Breakdown and Flashover Characteristics of PI with Different Temperature

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.709.11 ◽

2016 ◽

Vol 709 ◽

pp. 11-14

Author(s):

Tian Ye Niu ◽

Jia Xin Wu ◽

Ying Wen Li ◽

Dong Sheng Xu ◽

Lu Li ◽

...

Keyword(s):

Liquid Nitrogen ◽

Room Temperature ◽

Rapid Development ◽

Power Equipment ◽

Electrical Characteristics ◽

Cryogenic Temperatures ◽

Insulating Materials ◽

Dielectric Performance ◽

Working Performance

The electrical characteristics of insulating materials play a key role on the working performance and operation reliability of power equipment. With the rapid development of superconducting technology in recent years,the working temperature of high temperature superconducting power equipment can be controlled around the liquid nitrogen temperature. Due to its excellent dielectric performance and mechanical properties, polyimide have been widely used in power equipment at room temperature. However, polyimide, as a kind of cryogenic insulating materials, is rarely reported at present. Therefore, the study of the insulating characteristics of polyimide at the cryogenic temperatures is of great significance. The DC breakdown property and flashover performance of polyimide are tested around room temperature (300K) and liquid nitrogen temperature (78K). The results show that temperature has some effects on the DC breakdown property and flashover performance of polyimide.

Application of interference fits on cylindrical monochromator crystals to overcome clamping and cooling deformations

Journal of Synchrotron Radiation ◽

10.1107/s1600577519001061 ◽

2019 ◽

Vol 26 (2) ◽

pp. 382-385

Author(s):

Joshua Stimson ◽

Michael Ward ◽

John Sutter ◽

Sofia Diaz-Moreno ◽

Simon Alcock ◽

...

Keyword(s):

Heat Exchanger ◽

Liquid Nitrogen ◽

Room Temperature ◽

Silicon Crystal ◽

Cryogenic Cooling ◽

Element Analysis ◽

Thermal Interface ◽

Macro Scale ◽

Order Of Magnitude

In order to provide adequate cryogenic cooling of both existing and next-generation crystal monochromators, a new approach to produce an optimum thermal interface between the first crystal and its copper heat exchanger is proposed. This will ensure that the increased heat load deposited by higher X-ray powers can be properly dissipated. Utilizing a cylindrical silicon crystal, a tubular copper heat exchanger and by exploiting the differing thermal and mechanical properties of the two, a very good thermal interface was achieved at liquid-nitrogen temperatures. The surface flatness of the diffracting plane at one end of the cylindrical crystal was measured at room temperature while unconstrained. The crystal was then placed into the copper heat exchanger, a slide fit at room temperature, and then cooled to liquid-nitrogen temperature. At −200°C the slide fit became an interference fit. This room-temperature `loose' fit was modelled using finite-element analysis to obtain the desired fit at cryogenic temperatures by prescribing the fit at room temperature. Under these conditions, the diffraction surface was measured for distortion due to thermal and mechanical clamping forces. The total deformation was measured to be 30 nm, an order of magnitude improvement over deformation caused by cooling alone with the original side-clamped design this concept method is set to replace. This new methodology also has the advantage that it is repeatable and does not require macro-scale tools to acquire a nanometre-accuracy mounting.