Dynamic failure and adiabatic shearbands in fine-grain 93W–4.9Ni–2.1Fe alloy with Y2O3 addition under lower high-strain-rate (HSR) compression

Blow forming accompanied with superplasticity makes possible the forming of complex parts, which cannot be formed by cold press forming. The conventional superplastic AA5083 alloy ‘ALNOVI-1’ developed by the Furukawa-Sky Aluminum Corp. shows high superplasticity because of its fine grain and is widely used for blow forming. However, for mass production of components, an Al-Mg alloy with finer-sized grains is needed. In this research, the newly developed high Mn version of the Al-Mg alloy ‘ALNOVI-U’ is used, and this material possesses grains finer than those of the conventional AA5083 alloy. The effects of finer grain size on the blow formability at high strain rates over 10-2/s and the properties of the resulting moldings were studied.

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Microstructural examination in high-strain-rate superplastically deformed tetragonal ZrO2 dispersed with 30 vol% MgAl2O4 spinel

Journal of Materials Research ◽

10.1557/jmr.2007.0099 ◽

2007 ◽

Vol 22 (3) ◽

pp. 801-813 ◽

Cited By ~ 5

Author(s):

Koji Morita ◽

Keijiro Hiraga ◽

Byung-Nam Kim ◽

Yoshio Sakka

Keyword(s):

High Strain Rate ◽

Strain Rate ◽

High Strain ◽

Grain Boundary Sliding ◽

Dislocation Motion ◽

Particle Dispersion ◽

Stress Concentrations ◽

Fine Grain ◽

Pinning Effect ◽

Microstructural Examination

The role of MgAl2O4 spinel particle dispersion for attaining high-strain-rate superplasticity (HSRS) was examined in tetragonal ZrO2. Microstructural examination shows that the dispersed spinel particles provide the following positive factors to ZrO2 simultaneously: (i) stable fine grain size by retarding grain growth due to pinning effect; and (ii) enhanced accommodation due to accelerated lattice diffusivity caused by the dissolution of aluminum and magnesium into ZrO2 from the spinel particles, and accelerated relaxation of stress concentrations exerted by grain boundary sliding through dislocation motion. These positive factors make it possible to attain HSRS in ZrO2.

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Dynamic failure mechanisms of granular boron carbide under multi-axial high-strain-rate loading

Scripta Materialia ◽

10.1016/j.scriptamat.2019.08.003 ◽

2019 ◽

Vol 173 ◽

pp. 125-128 ◽

Cited By ~ 5

Author(s):

Ankur Chauhan ◽

Xiangyu Sun ◽

Kaliat T. Ramesh ◽

Kevin J. Hemker

Keyword(s):

High Strain Rate ◽

Boron Carbide ◽

Strain Rate ◽

High Strain ◽

Failure Mechanisms ◽

Dynamic Failure ◽

Strain Rate Loading

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Investigation on Deformation in ZK60 at High Strain Rate

Materials Science Forum ◽

10.4028/www.scientific.net/msf.488-489.527 ◽

2005 ◽

Vol 488-489 ◽

pp. 527-530

Author(s):

Xing Zhang ◽

Bao Cheng Li ◽

Zhi Min Zhang ◽

Zhi Wen Wang

Keyword(s):

Magnesium Alloy ◽

High Strain Rate ◽

Strain Rate ◽

Impact Velocity ◽

High Strain ◽

Dynamic Properties ◽

Deformation Behaviour ◽

Fine Grain ◽

Zk60 Alloy ◽

The Impact

Split Hopkinson Pressure Bars (SHPB) was applied to investigate shock resistance of magnesium alloy. The deformation behaviour was reported of ZK60 magnesium alloy at high strain rate, and the relationship was established between the dynamic properties and the impact velocity. Results indicate: with impact velocity improvement, much twinned crystal and fine grain can be obtianed, this made dynamic properties enhancement of ZK60 alloy.

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Modelling and Analysis of High Strain Rate Deformation at Elevated Temperature in Friction Stirring of Aluminum Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.838-839.110 ◽

2016 ◽

Vol 838-839 ◽

pp. 110-115

Author(s):

Katsuya Kumai ◽

Hiroki Fukushige ◽

Yoshimasa Takayama

Keyword(s):

Elevated Temperature ◽

High Strain Rate ◽

Strain Rate ◽

High Strain ◽

Frictional Heat ◽

High Temperature Deformation ◽

Temperature Deformation ◽

Friction Stir ◽

Fine Grain ◽

High Strain Rate Deformation

Friction stirring is a fundamental process in the friction stir welding (FSW), and moreover, high strain rate deformation in elevated temperature to lead to extremely high ductility and fine grain size. In the present study, friction stirring process has been successfully modelled as a high temperature deformation depending on strain rate and temperature, assuming shear deformation of material in stir zone and generation of frictional heat by rotating tool. Axial load and torque during the process were estimated based on the model, and compared with the experimental data at two kinds of combination ratio in FSW of aluminum and Al-Mg alloy. It was, consequently, confirmed that the model could evaluate flow stress and strain rate from the experimental load and torque.

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