scholarly journals Flow behavior and microstructure in Ti–6Al–4V alloy with an ultrafine-grained α-single phase microstructure during low-temperature-high-strain-rate superplasticity

2015 ◽  
Vol 66 ◽  
pp. 611-617 ◽  
Author(s):  
Hiroaki Matsumoto ◽  
Vincent Velay ◽  
Akihiko Chiba
Keyword(s):  
Low Temperature ◽  
High Strain Rate ◽  
Strain Rate ◽  
Single Phase ◽  
High Strain ◽  
Flow Behavior ◽  
Ultrafine Grained

scholarly journals High Strain Rate Superplasticity of WE54 Mg Alloy after Severe Friction Stir Processing

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1573
Author(s):  
Marta Álvarez-Leal ◽  
Fernando Carreño ◽  
Alberto Orozco-Caballero ◽  
Pilar Rey ◽  
Oscar A. Ruano
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Friction Stir Processing ◽  
High Strain ◽  
Flow Behavior ◽  
Traverse Speed ◽  
Grain Boundary Sliding ◽  
Coarse Grained ◽  
Friction Stir ◽  
Ultrafine Grained

Friction stir processing (FSP) was used on coarse-grained WE54 magnesium alloy plates of as-received material. These were subjected to FSP under two different cooling conditions, refrigerated and non-refrigerated, and different severe processing conditions characterized by low rotation rate and high traverse speed. After FSP, ultrafine equiaxed grains and refinement of the coarse precipitates were observed. The processed materials exhibited high resistance at room temperature and excellent superplasticity at the high strain rate of 10−2 s−1 and temperatures between 300 and 400 °C. Maximum tensile superplastic elongation of 726% was achieved at 400 °C. Beyond 400 °C, a noticeable loss of superplastic response occurred due to a loss of thermal stability of the grain size. Grain boundary sliding is the operative deformation mechanism that can explain the high-temperature flow behavior of the ultrafine grained FSP-WE54 alloy, showing increasing superplasticity with increasing processing severity.

Ti–6Al–4V alloy with an ultrafine-grained microstructure exhibiting low-temperature–high-strain-rate superplasticity

2013 ◽  
Vol 98 ◽  
pp. 209-212 ◽  
Author(s):  
Hiroaki Matsumoto ◽  
Kazuki Yoshida ◽  
San-Hak Lee ◽  
Yoshiki Ono ◽  
Akihiko Chiba
Keyword(s):  
Low Temperature ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Ultrafine Grained ◽  
Ultrafine Grained Microstructure

scholarly journals High Strain Rate Superplasticity in Al-Zn-Mg-Based Alloy: Microstructural Design, Deformation Behavior, and Modeling

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2098 ◽  
Author(s):  
Olga Yakovtseva ◽  
Maria Sitkina ◽  
Ahmed O. Mosleh ◽  
Anastasia Mikhaylovskaya
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Superplastic Deformation ◽  
High Strain ◽  
Flow Behavior ◽  
Constant Strain Rate ◽  
Superplastic Forming ◽  
High Strength ◽  
Strain Rate Range ◽  
Strain Rates

Increasing the strain rate at superplastic forming is a challenging technical and economic task of aluminum forming manufacturing. New aluminum sheets exhibiting high strain rate superplasticity at strain rates above 0.01 s−1 are required. This study describes the microstructure and the superplasticity properties of a new high-strength Al-Zn-Mg-based alloy processed by a simple thermomechanical treatment including hot and cold rolling. The new alloy contains Ni to form Al3Ni coarse particles and minor additions of Zr (0.19 wt.%) and Sc (0.06 wt.%) to form nanoprecipitates of the L12-Al3 (Sc,Zr) phase. The design of chemical and phase compositions of the alloy provides superplasticity with an elongation of 600–800% in a strain rate range of 0.01 to 0.6/s and residual cavitation less than 2%. A mean elongation-to-failure of 400% is observed at an extremely high constant strain rate of 1 s−1. The strain-induced evolution of the grain and dislocation structures as well as the L12 precipitates at superplastic deformation is studied. The dynamic recrystallization at superplastic deformation is confirmed. The superplastic flow behavior of the proposed alloy is modeled via a mathematical Arrhenius-type constitutive model and an artificial neural network model. Both models exhibit good predictability at low and high strain rates of superplastic deformation.

High strain-rate deformation of T8-tempered, cryo-rolled and ultrafine grained AA 2099 aluminum alloy

2019 ◽  
Vol 754 ◽  
pp. 602-612 ◽  
Author(s):  
A.G. Odeshi ◽  
A.A. Tiamiyu ◽  
D. Das ◽  
N. Katwal ◽  
I.N.A. Oguocha ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Ultrafine Grained ◽  
High Strain Rate Deformation

High-Strain-Rate Superplastic Flow Mechanism in ZrO2-30vol% Spinel Two-Phase Composite

2010 ◽  
Vol 433 ◽  
pp. 333-338 ◽  
Author(s):  
Koji Morita ◽  
Keijiro Hiraga ◽  
Byung Nam Kim ◽  
Hidehiro Yoshida
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Flow Behavior ◽  
Recovery Process ◽  
Lattice Diffusion ◽  
Two Phase ◽  
Data Set ◽  
Strain And Strain Rate ◽  
Accommodation Process

High-strain-rate superplasticity (HSRS) can be attained in tetragonal ZrO2-30vol% MgAl2O4 spinel composite. In order to examine the flow behavior of the two-phase composite, the standard rule of the mixture model was employed. The strain rate of the composite can be explained by the isostrain model that is predicted from the data set of Al2O3 doped ZrO2 and spinel polycrystals. For the isostrain model, since the strain and strain rate are the same for ZrO2 and spinel phases, the harder ZrO2 phase carries more of the stress in the composite. In order to preserve homogeneous deformation and material continuity, a concomitant accommodation process within the harder ZrO2 grains is also necessary. For HSRS in the ZrO2-spinel composite, therefore, the rate of deformation may be controlled by the slower dislocation recovery process limited by the lattice diffusion within harder ZrO2 grains rather than within spinel grains.

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