Ultrafine-grained magnesium–lithium alloy processed by high-pressure torsion: Low-temperature superplasticity and potential for hydroforming

It is now well-established that processing through the application of severe plastic deformation (SPD) leads to a significant reduction in the grain size of a wide range of metallic materials. This paper examines the fabrication of ultrafine-grained materials using high-pressure torsion (HPT) where this process is attractive because it leads to exceptional grain refinement with grain sizes that often lie in the nanometer or submicrometer ranges. Two aspects of HPT are examined. First, processing by HPT is usually confined to samples in the form of very thin disks but recent experiments demonstrate the potential for extending HPT also to bulk samples. Second, since the strains imposed in HPT vary with the distance from the center of the disk, it is important to examine the development of inhomogeneities in disk samples processed by HPT.

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High-strength state of ultrafine-grained martensitic steel produced by high pressure torsion

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/179/1/012037 ◽

2017 ◽

Vol 179 ◽

pp. 012037 ◽

Cited By ~ 4

Author(s):

M V Karavaeva ◽

M A Nikitina ◽

A V Ganeev ◽

R K Islamgaliev

Keyword(s):

High Pressure ◽

High Pressure Torsion ◽

Martensitic Steel ◽

High Strength ◽

Ultrafine Grained

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Mechanical and biological behavior of ultrafine-grained Ti alloy aneurysm clip processed using high-pressure torsion

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2017.02.002 ◽

2017 ◽

Vol 68 ◽

pp. 203-209 ◽

Cited By ~ 6

Author(s):

Ho Yong Um ◽

Byung Ho Park ◽

Dong-Hyun Ahn ◽

Mohamed Ibrahim Abd El Aal ◽

Jaechan Park ◽

...

Keyword(s):

High Pressure ◽

High Pressure Torsion ◽

Biological Behavior ◽

Ti Alloy ◽

Aneurysm Clip ◽

Ultrafine Grained

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Thermal Stability of Ultrafine-Grained Pure Titanium Processed by High-Pressure Torsion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1016.338 ◽

2021 ◽

Vol 1016 ◽

pp. 338-344

Author(s):

Wan Ji Chen ◽

Jie Xu ◽

De Tong Liu ◽

De Bin Shan ◽

Bin Guo ◽

...

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Grain Size ◽

High Pressure ◽

Annealing Temperature ◽

High Pressure Torsion ◽

Stored Energy ◽

Ultrafine Grained ◽

Average Grain Size ◽

Thermal Stability Of

High-pressure torsion (HPT) was conducted under 6.0 GPa on commercial purity titanium up to 10 turns. An ultrafine-grained (UFG) pure Ti with an average grain size of ~96 nm was obtained. The thermal properties of these samples were studied by using differential scanning calorimeter (DSC) which allowed the quantitative determination of the evolution of stored energy, the recrystallization temperatures, the activation energy involved in the recrystallization of the material and the evolution of the recrystallized fraction with temperature. The results show that the stored energy increases, beyond which the stored energy seems to level off to a saturated value with increase of HPT up to 5 turns. An average activation energy of about 101 kJ/mol for the recrystallization of 5 turns samples was determined. Also, the thermal stability of the grains of the 5 turns samples with subsequent heat treatments were investigated by microstructural analysis and Vickers microhardness measurements. It is shown that the average grain size remains below 246 nm when the annealing temperature is below 500 °C, and the size of the grains increases significantly for samples at the annealing temperature of 600 °C.

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