The Phenomenon of Superplasticity in Feal-Ti Alloy with Large Grains

1994 ◽  
Vol 364 ◽  
Author(s):  
Dingqiang Li ◽  
Aidang Shan ◽  
Yi Liu ◽  
Dongliang Lin
Keyword(s):  
Strain Rate ◽  
Superplastic Deformation ◽  
Dynamic Recovery ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Ti Alloy ◽  
Maximum Elongation ◽  
Rate Range ◽  
First Time ◽  
Range Of Values

AbstractThe phenomenon of superplasticity in an ordered FeAl based alloy is reported in this paper for the first time. The behavior of superplastic deformation for the FeAl based alloy (Fe-36.5at.%-2at.%Ti) with large grains of above 300 μm has been examined at 1000°C in a strain rate range from 1.39×10− 4 /s to 2.78×l0−2 /s. The maximum elongation of 208% for the FeAl based alloy with large grains has been obtained and the index of strain rate sensitivity, the m value, has a range of values from 0.25 to 0.42. The reason for the large elongation is ascribed to the dynamic recovery and recrystallization during deformation in this large grained alloy at high temperatures.

scholarly journals Study on Plastic Deformation Behavior of Mo-10Ta under Ultra-High Strain Rate

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1153
Author(s):  
Ping Song ◽  
Wen-Bin Li ◽  
Yu Zheng ◽  
Jiu-Peng Song ◽  
Xiang-Cao Jiang ◽  
...  
Keyword(s):  
Activation Energy ◽  
High Strain Rate ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Deformation Behavior ◽  
High Strain ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Rate Range ◽  
Strain Relationship

This study investigated the deformation behavior of the Mo-10Ta alloy with a strain rate range of 102–105 s−1. The Split Hopkinson pressure bar (SHPB) experiments were conducted to investigate the influence of deformation conditions on the stress-strain relationship and strain rate sensitivity of the material within a strain rate range of 0.001–4500 s−1. The Shaped Charge Jet (SCJ) forming experiments under detonation loading was conducted to clarify the dynamic response and microstructure evolution of the material within an ultra-high strain rates range of 104–105 s−1. Based on the stress-strain relationship of Mo-10Ta alloy at high temperature (286–873 K) and high strain rate (460–4500 s−1), the influence of temperature and strain rate on the activation energy Q was analyzed. The results indicate that the material strain rate sensitivity increased with the increase in strain rate and strain. Meanwhile, the activation energy Q decreased as the temperature and strain rate increased. The plasticity of the Mo-10Ta alloy under the condition of SCJ forming was substantially enhanced compared with that under quasi-static deformation. The material grain was also refined under ultra-high strain rate, as reflected by the reduction in grain size from 232 μm to less than 10 μm.

The Influence of Microstructure on Superplastic Behaviours of γ-TiAl Alloys

1998 ◽  
Vol 552 ◽  
Author(s):  
J. Sun ◽  
J. S. Wu ◽  
G. X. Hu ◽  
Y. H. He ◽  
B. Y. Huang
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Superplastic Deformation ◽  
Rate Sensitivity ◽  
Strain Rates ◽  
Maximum Elongation ◽  
Tial Alloys ◽  
Different Temperatures ◽  
Incremental Strain

ABSTRACTIn this work, superplastic behaviours in Ti-33A1–3Cr-0.5Mo (wt%) γ-TiAl alloys with two different initial microstructures of near gamma (NG) and duplex (DM) structure were investigated with respect to the effect of testing temperatures and strain rates. At 1050°C and a strain rate of 8×10–5 S–1, a maximum elongation of 570% was observed for NG-TiAl and a maximum elongation of 467% for DM-TiAl. The relations of flow stress and strain rate sensitivity vs. strain rates at different temperatures were also determined by incremental strain rate tests. The results showed that the value of strain rate sensitivity is higher and the flow stress is lower for NG than those for DM at the same condition. The microstructural evolution during superplastic deformation was examined and correlated to the mechanical properties for these two alloys. The influence of microstructure on the superplastic behaviours of γ-TiAl alloys, and possible superplastic deformation mechanisms were finally discussed.

Hot Deformation Behavior of SiCw/AZ91 Magnesium Matrix Composite in Compression

2005 ◽  
Vol 475-479 ◽  
pp. 893-896
Author(s):  
S.B. Li ◽  
Ming Yi Zheng ◽  
Wei Min Gan ◽  
Kun Wu
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Dynamic Recovery ◽  
True Strain ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Magnesium Matrix ◽  
Sic Whiskers ◽  
Az91 Magnesium ◽  
Activation Energy Of Deformation

The compressive behavior of squeeze cast SiCw/AZ91 composite in the temperature range of 423-723K and in the strain rate range of 0.001-0.25 s-1 was investigated. The compressive true stress-true strain curves were measured and hot deformation microstructures were observed. The strain rate sensitivity exponent (m) of the SiCw/AZ91 composite increased with the increasing of temperature. The activation energy of deformation varied over the range of test conditions examined indicated that the deformation was controlled by more than one mechanism. The reorientation of SiC whiskers in the composite was observed during compression. During the compression, dynamic recovery and dynamic recrystallization occurred in the SiCw/AZ91 composite.

scholarly journals Effect of Strain Rate on the Mechanical Properties of Cu/Ni Clad Foils

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6846
Author(s):  
Haiyang Wang ◽  
Chuanjie Wang ◽  
Linfu Zhang ◽  
Gang Chen ◽  
Qiang Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Rate Sensitivity ◽  
Interface Layer ◽  
Strain Rate Range ◽  
Coarse Grained ◽  
Uniaxial Tensile ◽  
Rate Range ◽  
Static Strain

The performance of clad foils in microforming deserves to be studied extensively, where the strain rate sensitivity of the clad foil concerning the forming performance is a crucial factor. In this paper, the strain rate sensitivity of the mechanical properties of coarse-grained (CG) Cu/Ni clad foils in the quasi-static strain rate range (ε˙=10−4 s−1~10−1 s−1) is explored by uniaxial tensile tests under different strain rates. The results show that the strength and ductility increase with strain rate, and the strain rate sensitivity m value is in the range of 0.012~0.015, which is three times the value of m for CG pure Cu. The fracture morphology shows that slip bands with different directions are entangled in localized areas near the interface layer. Molecular dynamics simulations demonstrate the formation of many edged dislocations at the Cu/Ni clad foils interface due to a mismatch interface. The improved ductility and strain rate sensitivity is attributed to the interaction and plugging of the edged dislocations with high density in the interface layer. Additionally, the influence of size effect on mechanical properties is consistently present in the quasi-static strain rate range. This paper helps to understand the strain rate sensitivity of CG clad foils and to develop clad foils in microforming processes.

Effect of Strain Rate on Constitutive Behavior of AA-5052 H34

2013 ◽  
Vol 535-536 ◽  
pp. 60-63 ◽  
Author(s):  
Prince Sharma ◽  
Pradeep Chandel ◽  
Vikas Mangla ◽  
Puneet Mahajan ◽  
Manjit Singh
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Split Hopkinson Pressure Bar ◽  
Rate Sensitivity ◽  
Tensile Tests ◽  
Strain Rate Range ◽  
Gauge Length ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Rate Range

This paper presents the experimental results to analyze the strain rate sensitivity of aluminium alloy AA-5052 H34. The experiments were carried out under uniaxial tension as well as compression. Tensile tests were carried out with UTM (Zwick Z-250) in the strain rate range of 10-4 to 10-1 s-1 using standard ASTM specimen with gauge length 50mm. Compression tests were carried out in the strain rate range of 10-4 to 103 s-1 using UTM and Split Hopkinson Pressure Bar. Cylindrical specimens of 10mm diameter and 10mm thickness were used for compression experiments. The material showed negative strain rate sensitivity in strain rate from 10-4 to 1 s-1 but showed positive strain rate sensitivity when strain rate increased to 103 s-1. The material was found to be susceptible to Portevin–Le Chatelier effect.

scholarly journals Superplasticity of Ti-6Al-4V Titanium Alloy: Microstructure Evolution and Constitutive Modelling

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1756 ◽  
Author(s):  
Ahmed O. Mosleh ◽  
Anastasia V. Mikhaylovskaya ◽  
Anton D. Kotov ◽  
James S. Kwame ◽  
Sergey A. Aksenov
Keyword(s):  
Strain Rate ◽  
Microstructural Evolution ◽  
Deformation Temperature ◽  
Superplastic Deformation ◽  
Deformation Behaviour ◽  
Strain Rate Range ◽  
Grain Structure ◽  
Rate Range ◽  
Temperature Range ◽  
Elongation To Failure

Determining a desirable strain rate-temperature range for superplasticity and elongation-to-failure are critical concerns during the prediction of superplastic forming processes in α + β titanium-based alloys. This paper studies the superplastic deformation behaviour and related microstructural evolution of conventionally processed sheets of Ti-6Al-4V alloy in a strain rate range of 10–5–10–2 s–1 and a temperature range of 750–900 °C. Thermo-Calc calculation and microstructural analysis of the as-annealed samples were done in order to determine the α/β ratio and the grain size of the phases prior to the superplastic deformation. The strain rate ranges, which corresponds to the superplastic behaviour with strain rate sensitivity index m ˃ 0.3, are identified by step-by-step decreasing strain rate tests for various temperatures. Results of the uniaxial isothermal tensile tests at a constant strain rate range of 3 × 10−4–3 × 10−3 s−1 and a temperature range of 800–900 °C are presented and discussed. The experimental stress-strain data are utilized to construct constitutive models, with the purpose of predicting the flow stress behaviour of this alloy. The cross-validation approach is used to examine the predictability of the constructed models. The models exhibit excellent approximation and predictability of the flow behaviour of the studied alloy. Strain-induced changes in the grain structure are investigated by scanning electron microscopy and electron backscattered diffraction. Particular attention is paid to the comparison between the deformation behaviour and the microstructural evolution at 825 °C and 875 °C. Maximum elongation-to-failure of 635% and low residual cavitation were observed after a strain of 1.8 at 1 × 10−3 s−1 and 825 °C. This temperature provides 23 ± 4% β phase and a highly stable grain structure of both phases. The optimum deformation temperature obtained for the studied alloy is 825 °C, which is considered a comparatively low deformation temperature for the studied Ti-6Al-4V alloy.

Plastic Deformation at High Temperature and Processing Map of AZ61 Magnesium Alloy

2014 ◽  
Vol 926-930 ◽  
pp. 182-185
Author(s):  
Quan Li ◽  
Wen Jun Liu ◽  
Ren Ju Cheng ◽  
Shan Jiang ◽  
Su Qin Luo ◽  
...  
Keyword(s):  
Strain Rate ◽  
Power Dissipation ◽  
Deformation Behavior ◽  
Processing Map ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Processing Maps ◽  
Rate Range ◽  
Optimum Parameters ◽  
Az61 Magnesium Alloy

The deformation behavior of as-cast AZ61 alloy in the temperature range 300-450°C and in the strain rate range 0.01~5 s−1 has been studied using processing maps. For obtaining the processing map, the variation of the efficiency of power dissipation given by [2m/(m+1)] where ‘m’ is the strain rate sensitivity, is plotted as a function of temperature and strain rate. The map exhibited a domain of dynamic recrystallization (DRX) occurring at 425 °C and 0.1 s−1 which are the optimum parameters for hot working of the alloy.

Deformation resistance and fracture of iron over a wide strain rate range

2014 ◽  
Vol 56 (8) ◽  
pp. 1569-1573 ◽  
Author(s):  
G. I. Kanel ◽  
S. V. Razorenov ◽  
G. V. Garkushin ◽  
S. I. Ashitkov ◽  
P. S. Komarov ◽  
...  
Keyword(s):  
Strain Rate ◽  
Strain Rate Range ◽  
Deformation Resistance ◽  
Rate Range

scholarly journals Study on the dynamic properties of AM-SLM AlSi10Mg alloy using the Split Hopkinson Pressure Bar (SHPB) technique

2018 ◽  
Vol 183 ◽  
pp. 04005 ◽  
Author(s):  
Bar Nurel ◽  
Moshe Nahmany ◽  
Adin Stern ◽  
Nahum Frage ◽  
Oren Sadot
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Static Mechanical ◽  
Split Hopkinson ◽  
Pressure Bar

Additive manufacturing by Selective Laser Melting of metals is attracting substantial attention, due to its advantages, such as short-time production of customized structures. This technique is useful for building complex components using a metallic pre-alloyed powder. One of the most used materials in AMSLM is AlSi10Mg powder. Additively manufactured AlSi10Mg may be used as a structural material and it static mechanical properties were widely investigated. Properties in the strain rates of 5×102–1.6×103 s-1 and at higher strain rates of 5×103 –105 s-1 have been also reported. The aim of this study is investigation of dynamic properties in the 7×102–8×103 s-1 strain rate range, using the split Hopkinson pressure bar technique. It was found that the dynamic properties at strain-rates of 1×103–3×103 s-1 depend on a build direction and affected by heat treatment. At higher and lower strain-rates the effect of build direction is limited. The anisotropic nature of the material was determined by the ellipticity of samples after the SHPB test. No strain rate sensitivity was observed.

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