Softening Phenomenon during Compression Test in Nanograined Aluminum Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 3489-3492 ◽  
Author(s):  
Se Hyun Ko ◽  
Jin Man Jang ◽  
Won Sik Lee
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloys ◽  
Strain Rate ◽  
Strain Hardening ◽  
Compression Test ◽  
Room Temperature ◽  
Strain Rate Range ◽  
Rate Range ◽  
Cu Alloys ◽  
Deformation Behaviors

Al-Mg and Al-Mg-Cu alloys are known well to reveal superplasticity in tension at high temperatures. In this study, deformation behaviors of those alloys nanograined were investigated under compression test at room temperature. During plastic deformation softening phenomena occurred obviously in nanograined Al-1.5wt%Mg and Al-0.7wt%Mg-1.0wt%Cu alloys while slight strain hardening appeared in nanograined pure Al. These results suggest that the softening strongly depends on composition of alloys. The softening takes place over strain rate range from 10-4 up to 10-1.

Temperature and Strain Rate Dependence of Deformation Microstructures of AZ31 Magnesium Alloy under Uniaxial Tension

2011 ◽  
Vol 217-218 ◽  
pp. 93-96 ◽  
Author(s):  
Wan Peng Deng ◽  
Zhan Feng Gao ◽  
Xiao Wu Li
Keyword(s):  
Strain Rate ◽  
Room Temperature ◽  
Tensile Deformation ◽  
Flow Behavior ◽  
Strain Rate Range ◽  
Mg Alloy ◽  
Rate Range ◽  
Deformation Twins ◽  
Az31 Mg Alloy ◽  
Increasing Temperature

The tensile deformation microstructures of an extruded AZ31 Mg alloy were examined at temperatures ranging from room temperature to 250°C over a strain rate range from 10-4 s-1 to 10-2 s-1. It is found that the strain rate has an enhanced effect on the tensile flow behavior of AZ31 Mg alloy with increasing temperature, which is closely related to the changes of deformation microstructures. The tensile deformation of AZ31 Mg alloy is mainly accommodated by twinning and slipping at room temperature and 100°C, and the amount of deformation twins reduces with increasing temperature and decreasing strain rate. However, discontinuous dynamic recrystallization (DRX) occurs primarily at grain boundaries, and nearly no deformation twins form, as the temperature is as high as 250°C. With decreasing strain rate, more significant DRX takes place with an increasing DRX grain size. The tensile deformation of AZ31 Mg alloy at 250°C is thus primarily controlled by slipping and DRX.

scholarly journals High Temperature Behaviors of a Casting Nickel-Based Superalloy Used for 815 °C

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 716
Author(s):  
Jiangping Yu ◽  
Donghong Wang ◽  
Jingyang Chen ◽  
Changlin Yang ◽  
Xin Hao ◽  
...  
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Deformation Condition ◽  
Strain Rates ◽  
Rate Range ◽  
Temperature Range ◽  
Nickel Based Superalloy ◽  
Deformation Behaviors

The hot deformation behaviors of the SJTU-1 alloy, the high-throughput scanned casting Nickel-based superalloy, was investigated by compression test in the temperature range of 900 to 1200 °C and strain rate range of 0.1–0.001 s−1. The hot processing map has been constructed with the instability zone. At the beginning of hot deformation, the flow stress moves rapidly to the peak value with the increased strain rates. Meanwhile, the peak stress is decreased with the increased temperature at the same strain rates. However, the peak stress shows the same tendency with the strain rates at the same temperature. The optimum hot deformation condition was determined in the temperature range of 1000–1075 °C, and the strain rate range of 0.005–0.1 s−1. The microstructure investigation indicates the strain rate significantly affects the characteristics of the microstructure. The deformation constitutive equation has also been discussed as well.

scholarly journals Strain Rate Dependence of Material Strength in AA5xxx Series Aluminum Alloys and Evaluation of Their Constitutive Equation

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 576 ◽  
Author(s):  
Hiroyuki Yamada ◽  
Tsuyoshi Kami ◽  
Ryota Mori ◽  
Tomoyuki Kudo ◽  
Minemitsu Okada
Keyword(s):  
Aluminum Alloys ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Strain Rate Range ◽  
Rate Dependence ◽  
Strain Rate Dependence ◽  
Dynamic Strain ◽  
Material Strength ◽  
Rate Range ◽  
Aa5182 Alloy

The effect of strain rate on the mechanical properties of AA5xxx series aluminum alloys containing solute Mg atoms (AA5005, AA5021, AA5082 and AA5182) and pure aluminum (A1070) was investigated within a wide strain rate range of 1.0 × 10−4 to 1.0 × 103 s−1 at room temperature. The A1070 exhibited a positive strain rate dependence of material strength at the investigated strain rates. However, the AA5xxx series aluminum alloys primarily exhibited the negative strain rate dependence of material strength and serration caused by the Portevin-Le Chatelier effect on the Mg content and strain rate. As a result of using the material constitutive equation for the negative strain rate dependence, it was found that the flow stress may change in the dynamic strain rate range. However, it was found that the strain rate dependence of material strength differed in the AA5082 and the AA5182 alloys. It would be caused by less solute Mg of the Al phase in the AA5182 alloy than in the AA5082 alloy, because more Mg2Si compounds precipitated on Mn bearing particles as precipitation sites in the AA5182 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

Tensile Stress-Strain Curves Modeling of Four Kinds of Solders with Temperature and Rate Dependence

2005 ◽  
Vol 297-300 ◽  
pp. 905-911 ◽  
Author(s):  
Xu Chen ◽  
Li Zhang ◽  
Masao Sakane ◽  
Haruo Nose
Keyword(s):  
Tensile Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Strain Rate Range ◽  
Rate Dependence ◽  
Strain Rates ◽  
Stress Strain ◽  
Rate Range

A series of tensile tests at constant strain rate were conducted on tin-lead based solders with different Sn content under wide ranges of temperatures and strain rates. It was shown that the stress-strain relationships had strong temperature- and strain rate- dependence. The parameters of Anand model for four solders were determined. The four solders were 60Sn-40Pb, 40Sn-60Pb, 10Sn-90Pb and 5Sn-95Pb. Anand constitutive model was employed to simulate the stress-strain behaviors of the solders for the temperature range from 313K to 398K and the strain rate range from 0.001%sP -1 P to 2%sP -1 P. The results showed that Anand model can adequately predict the rate- and temperature- related constitutive behaviors at all test temperatures and strain rates.

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.

Strain Rate Sensitivity of Ultrafine-Grained CP-Ti Processed by ECAP at Room Temperature

2010 ◽  
Vol 667-669 ◽  
pp. 707-712 ◽  
Author(s):  
Xiao Yan Liu ◽  
Xi Cheng Zhao ◽  
Xi Rong Yang
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Room Temperature ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Compression Tests ◽  
Ultrafine Grained ◽  
Die Set ◽  
Increasing Temperature ◽  
Cp Ti

Ultrafine-grained (UFG) commercially pure (CP) Ti with a grain size of about 200 nm was produced by ECAP up to 8 passes using route BC at room temperature. For ECAP processing a proper die set was designed and constructed with an internal channel angle Φ of 120° and an outer arc of curvature Ψ of 20°. Strain rate sensitivity of UFG CP-Ti and CG CP-Ti were investigated by compression tests in the temperature range of 298~673K and strain rate range of 10-4~100s-1 using Gleeble simulator machine. Evolution of the microstructure during compression testing was observed using optical microscopy (OM) and transmission electron microscopy (TEM). Strain rate sensitivity value m of the UFG CP-Ti has been measured and is found to increase with increasing temperature and decreasing strain rate, and is enhanced compared to that of CG CP-Ti. Result of the deformation activation energy determination of UFG CP-Ti indicates that the deformation mechanism in UFG CP-Ti is correlated to the grain boundaries.

Extraordinary High Strain Rate Superplasticity of an Al-Mg-Sc-Zr Alloy Subjected to Equal Channel Angular Pressing

2012 ◽  
Vol 735 ◽  
pp. 295-300
Author(s):  
Elena Avtokratova ◽  
Oleg Sitdikov ◽  
Michael Markushev ◽  
Radik R. Mulyukov
Keyword(s):  
Strain Rate ◽  
Equal Channel Angular Pressing ◽  
High Strain ◽  
Strain Rate Range ◽  
Rate Range ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Excess Phases ◽  
Ultrafine Grained Microstructure ◽  
Zr Alloy

Unique superplastic elongations up to 4100% were achieved at 450°C in the strain rate range of 10-2-10-1s-1for Al-Mg-Sc-Zr alloy with a grain size ~1 μm processed by warm-to-hot equal channel angular pressing. Such a behavior is attributed to the synergy of complementary factors resulted in high homogeneity and stability of ultrafine-grained microstructure and superplastic flow, involving large proportion of high-angle grain boundaries, presence of dispersoids of aluminides of transition metals and negligible amount of coarse excess phases.

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