scholarly journals Dynamic Mechanical Behavior and Microstructure Evolution of an Extruded 6013-T4 Alloy at Elevated Temperatures

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 629 ◽  
Author(s):  
Tuo Ye ◽  
Yuanzhi Wu ◽  
Wei Liu ◽  
Bin Deng ◽  
Anmin Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Stress Level ◽  
Microstructure Evolution ◽  
Elevated Temperatures ◽  
Strain Rate Range ◽  
Rate Range ◽  
Dynamic Mechanical Behavior ◽  
Strain And Strain Rate ◽  
Increasing Temperature

The mechanical properties of an extruded 6013-T4 alloy were tested at a temperature range from 25 to 400 °C and strain rate range from 1 × 103 to 5 × 103 s−1. The results demonstrate that the stress level is sensitive to strain rate and temperature. The stress level increases slightly with increasing strain rate and decreases remarkably with increasing temperature. The dislocation and precipitate undergo great changes. When deformed at 25 °C, the density of the dislocation increases with strain and strain rate; which leads to a higher stress level. A great number of needle-like precipitates were observed at samples deformed at 200 °C. It is clear that the density of dislocation increases with strain and strain rate. When impacted at 400 °C, the coarser precipitates were found in the specimen; the density of the dislocation increases with strain and strain rate.

scholarly journals Investigation of mechanical properties of limesand brick under dynamic loading

2018 ◽  
Vol 174 ◽  
pp. 02018
Author(s):  
Anatoliy Bragov ◽  
Andrey Lomunov ◽  
Alexander Konstantinov ◽  
Dmitriy Lamzin ◽  
Leopold Kruszka
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Strain Rate ◽  
Dynamic Loading ◽  
Energy Intensity ◽  
Strain Rate Range ◽  
Brazilian Test ◽  
Stress Rate ◽  
Rate Range ◽  
Kolsky Method

The results of experimental study of mechanical properties of samples of lime-sand brick under dynamic loading are presented. The tests were carried out using the traditional Kolsky method and its modification - dynamic splitting (the so-called «Brazilian test»). The laws of change in strength, strain, time properties and energy intensity of the investigated material are established in the strain rate range of 5·102-2.5·103 s-1 under compression and in the stress rate range of 2·101-3·102 GPa/s under tension.

Research on the Semi-Solid Compressive Deformation Behavior of Ti-7Cu Alloy

2016 ◽  
Vol 35 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Yongnan Chen ◽  
Chuang Luo ◽  
Jiao Wang ◽  
Yongqing Zhao ◽  
Hong Chen
Keyword(s):  
Titanium Alloy ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Strain Rate Range ◽  
Rate Range ◽  
Solid Deformation ◽  
Pile Up ◽  
Compressive Testing ◽  
Semi Solid ◽  
Increasing Temperature

AbstractThe semi-solid deformation behavior of Ti-7Cu titanium alloy in the temperature range of 1,223 K to 1,473 K and strain rate range of 0.005 to 5 s−1 have been investigated by hot compressive testing. The results show that the maximum and stability stresses decrease with decreasing strain rate and increasing temperature. A yielding occurred to the alloy at a higher strain rate under all experimental temperatures. The flow behaviors were described by a constitutive equation based on the Arrhenius equations and the deformation activate energies is also calculated. By comparing with microstructure of the solid deformation, the liquid in semi-solid deformation can overcome the restriction of the movement of solid particle, which reduced the dislocation pile-up during deformation and caused low deformation resistant stress.

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.

scholarly journals Experimental Study on the Influence of Freezing Pressure on the Uniaxial Mechanical Properties of Ice

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Baosheng Wang ◽  
Weihao Yang ◽  
Peixin Sun ◽  
Xin Huang ◽  
Yaodan Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Strain Rate ◽  
Uniaxial Compression ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Brittleness Index ◽  
Rate Range ◽  
Minimum Value ◽  
Maximum Minimum

In this study, a test technique that enables continuous control of the sample stress state from freezing to testing is proposed to investigate the influence of freezing pressure on the mechanical properties of ice under uniaxial compression. In this method, the water is frozen into the standard cylindrical ice specimen under high hydraulic pressure in a triaxial pressure chamber, and then, the temperature field and stress field of the ice specimens are adjusted to the initial state of the test; finally, an in situ mechanical test is conducted in the triaxial chamber. The uniaxial compression test of ice specimens with temperature of −20°C and freezing pressure of 0.5–30 MPa is performed in the strain rate range of 5 × 10−5−1.5 × 10−6 s−1. The results show that, as the freezing pressure increases, the ductile-to-brittle transition zone of the ice specimen during failure moves to the low strain rate range, and the failure mode of the specimen changes from shear failure to splitting failure. Further, the brittleness index of the ice specimen first increases, then decreases, and then again increases with the increase in freezing pressure. The brittleness index reaches the maximum (minimum) when the freezing pressure is 30 MPa (20 MPa). The peak stress of the ice specimen also increases first, then decreases, and then increases with the increase in freezing pressure. The maximum value is also at the freezing pressure of 30 MPa, but the minimum value is obtained at the freezing pressure of 0.5 MPa. The failure strain of the ice specimen first decreases and then increases with the increase in freezing pressure, and the maximum (minimum) value is achieved at the freezing pressure of 0.5 MPa (10 MPa). When the ice specimen exhibits brittle failure, the relationships between the residual stress and the freezing pressure and between the peak stress and freezing pressure are the same, but when the ice specimen exhibits ductile failure, there is no obvious relationship between the residual stress and the freezing pressure.

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.

High Strain Rate Deformation Behavior of Mg–Al–Zn Alloys at Elevated Temperatures

2007 ◽  
Vol 340-341 ◽  
pp. 107-112 ◽  
Author(s):  
Hiroyuki Watanabe ◽  
Koichi Ishikawa ◽  
Toshiji Mukai
Keyword(s):  
High Temperature ◽  
High Strain Rate ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Elevated Temperatures ◽  
High Strain ◽  
Strain Rate Range ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Rate Range

High temperature deformation behavior of AZ31 and AZ91 magnesium alloys was examined by compression tests over a wide strain rate range from 10–3 to 103 s–1 with emphasis on the behavior at high strain rates. The dominant deformation mechanism in the low strain rate range below 10–1 s–1 was suggested to be climb-controlled dislocation creep. On the other hand, experimental results indicated that the deformation at a high strain rate of ~103 s–1 proceeds by conventional plastic flow of dislocation glide and twinning even at elevated temperatures. The solid-solution strengthening was operative for high temperature deformation at ~103 s–1.

DYNAMIC TENSILE AND COMPRESSIVE STRESS-STRAIN CHARACTERISTICS OF MAGNESIUM ALLOYS AT ELEVATED TEMPERATURES

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1135-1140 ◽  
Author(s):  
TEPPEI ARAMOTO ◽  
HIROSHI TACHIYA ◽  
AKIYOSHI HORI ◽  
AKIHIRO HOJO ◽  
YUSUKE MIYAZAKI
Keyword(s):  
Strain Rate ◽  
Magnesium Alloys ◽  
Dynamic Stress ◽  
Elevated Temperatures ◽  
Compressive Load ◽  
Tensile Load ◽  
Strain Rate Range ◽  
Stress Strain ◽  
Rate Range ◽  
Temperature Ranges

The dynamic stress-strain characteristics of magnesium alloys have not been clarified sufficiently. Thus, the study investigated both the compressive and tensile dynamic stress-strain characteristics of representative magnesium alloys: AZ61A-F, ZK60A-T5 and AZ31B-F at wide strain rate and temperature ranges. About the strain rate dependency, the dynamic stresses are higher than the static ones under both compressive and tensile loads at elevated temperatures; however the dynamic stress-strain relations change slightly in the dynamic strain rate range. Thus, the magnesium alloys has little strain rate dependence. However, the elongation of the dynamic stress-strain relations under tensile load tends to be larger than that of static one. About the temperature dependency, the yield and flow stresses of the investigated magnesium alloys under compressive load decrease abruptly at temperatures higher than about 600 K in the wide strain rate range. Meanwhile, the ones under tensile load decrease with the temperature more gently. Totally, the magnesium alloys exhibit low temperature dependence. Furthermore, as well known, the yield stresses caused under the tensile load exhibit about twice as high as those under compressive load. This study verified that such a characteristic can be observed over a wide strain rate and temperature ranges.

Experimental Study of In-plane Mechanical Properties of Carbon Fibre Woven Composite at Different Strain Rates

2017 ◽  
Vol 25 (4) ◽  
pp. 289-298 ◽  
Author(s):  
Jiahai Lu ◽  
Ping Zhu ◽  
Qinghui Ji ◽  
Zhang Cheng
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibre ◽  
Strain Rate ◽  
Complex Loading ◽  
Axial Direction ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Woven Composite ◽  
Rate Range ◽  
Failure Patterns

Carbon fibre woven composite has been increasingly employed in engineering applications undergoing complex loading conditions. For effective use of composite material in dynamic applications, it is essential to fully understand the mechanical behaviour of composite at different strain rates. In the present study, both in-plane tensile and compressive experiments loaded at 0 degree axial direction and 45 degree off-axial direction of a TC33 carbon fibre woven composite were investigated over the strain rate range from 0.001 to 1000 s−1. High strain rate tests were carried out using Split Hopkinson Pressure and Tensile Bar apparatus respectively. The results indicated that the in-plane mechanical properties and failure patterns were strain rate sensitive under both tensile and compressive loadings. The mechanical properties, failure patterns and strain rate effect also showed highly direction dependent and tension/compression asymmetric characteristic within the considered strain rate range. For higher strain rate sensitivity under compression than that under tension, the asymmetry of mechanical properties was less obvious with the increase of strain rate. Finally, two phenomenal models were proposed to quantitatively fit the relationship between strength property and strain rate.

Tensile Properties of MoSi2 at Elevated Temperatures

2004 ◽  
Vol 449-452 ◽  
pp. 845-848 ◽  
Author(s):  
Ai Dang Shan ◽  
Jian Sheng Wu ◽  
Hitoshi Hashimoto ◽  
Yong Ho Park
Keyword(s):  
Activation Energy ◽  
Grain Size ◽  
Strain Rate ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
Strain Rate Range ◽  
Rate Range ◽  
Energy Value ◽  
Lower Strain ◽  
Ductility Maximum

The tensile properties of two MoSi2 alloys with different grain sizes (1 micrometer and 10 micrometer) were evaluated in vacuum at temperatures ranging from 1400 to 1600K and initial strain rates ranging from 1×10-5/s to 1×10-3/s. For the alloy with 10micron grain size an m vale of 0.35 and an activation energy value of 350 kJ/mol were observed in the lower strain rate range while an m value of 0.12 and an activation energy value of 760 kJ/mol were observed in the higher strain rate range. For the alloy with 1micron grain size, a uniform m value of 0.55 and an activation energy value of 160 kJ/mol were observed. Moreover these two alloys showed remarkable ductility (maximum 33%) in the test temperatures. The deformation mechanism and the remarkable ductility are discussed in the light of the microstructural observations through SEM and TEM.

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