Deformation and Fracture Behavior of 7039 Al Reinforced with B4C Particles at Elevated Temperature

2007 ◽  
Vol 351 ◽  
pp. 65-69 ◽  
Author(s):  
Cun Zhu Nie ◽  
Jia Jun Gu ◽  
Jun Liang Liu ◽  
Di Zhang
Keyword(s):  
Elevated Temperature ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Aluminum Matrix ◽  
Rate Sensitivity ◽  
Initial Strain Rate ◽  
Initial Strain ◽  
Temperature Deformation ◽  
Uniaxial Tensile ◽  
Deformation And Fracture

The elevated temperature deformation and fracture behavior of an 10vol%B4CP/7039 aluminum matrix composite plate was investigated by uniaxial tensile tests at temperatures ranging from573 to 773 K and at initial strain rates from 1x10-1 to 1x10-4s-1.The strain rate sensitivity exponent was found to be approximately 0.1-0.15 which was below that of a superplastic material. A maximum elongation of 116% was obtained at an initial strain rate of 10-1 s-1 and at a temperature of 773 K.

scholarly journals Regularities of Low-Temperature Deformation and Fracture of Polyimide Films of Kapton H Type of Different Thickness

2020 ◽  
Keyword(s):  
Strain Rate ◽  
Thick Film ◽  
Sharp Decrease ◽  
Rate Sensitivity ◽  
Temperature Deformation ◽  
Relative Deformation ◽  
Polyimide Films ◽  
Deformation Curves ◽  
Deformation And Fracture ◽  
First Time

The mechanical characteristics (limit of forced elasticity σforc, fracture stress σfr, relative deformation to failure εfr) of polyimide films of kapton H type under uniaxial tension conditions along the direction of drawing in the temperature range (4.2-293 K), deformation rates (10-5 - 10-3 s-1) and film thicknesses (25, 75 and 125 μm) were investigated. It is discovered, that the forced-elastic state remains for all films up to 4.2 K of all strain rates - σfors<σfr. In this case, the reserve of elasticity significantly depends on the thickness of the film with a decrease in temperature. A sharp decrease in εfr occurs in films: 125 μm thick - at 77 K, 75 μm thick - at 4.2 K. Two variants of deformation curves are possible in a 25 μm thick film at 4.2 K: with a short nonlinear stage or with a long one proceeding jumpily. The working surface of the samples that have undergone jump deformation is covered with a deformation relief, partially representing a delayed highly elastic deformation. The σfors limit is most sensitive to the strain rate. The nature of the strain rate sensitivity σfors(έ) depends on the temperature and film thickness. The change to the opposite in the character of σfors(έ) and σfr(έ) with a decrease in temperature to 4.2 K in 75 and 125 thick films was found for a first time. Change in the character of σfors(έ) is not observed in 25 μm thick film which retains the maximum reserve of elasticity at 4.2 K

Superplasticity of an AA2519 Aluminum Alloy

2016 ◽  
Vol 838-839 ◽  
pp. 278-284
Author(s):  
Ivan Zuiko ◽  
Marat Gazizov ◽  
Rustam Kaibyshev
Keyword(s):  
Strain Rate ◽  
Thermomechanical Processing ◽  
Rate Sensitivity ◽  
Initial Strain Rate ◽  
Tensile Tests ◽  
Sensitivity Coefficient ◽  
Initial Strain ◽  
Strain Rates ◽  
Average Grain Size ◽  
Elongation To Failure

A commercial AA2519 alloy with a chemical composition of Al-5.64Cu-0.33Mn-0.23Mg-0.15Zr (in wt. %) was subjected to two-step thermomechanical processing (TMP) providing the formation of fully recrystallized structure with an average grain size of ~7 mm in 3 mm thin sheets. Superplastic tensile tests were performed in the temperature interval 450-535°C and initial strain rates ranging from ~2.8 x 10-4 to ~6.0 x 10-1 s-1. The highest elongation-to-failure of ~750% appears at a temperature of ~525°C and an initial strain rate of ~1.4 × 10-4 s-1 with the corresponding strain rate sensitivity coefficient of ~0.46.

Superplasticity-Like Behavior, Microstructures and Deformation Mechanism Map in Superlight Mg-6Li-3Zn Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 2504-2510
Author(s):  
Fu Rong Cao ◽  
Ren Guo Guan ◽  
Hua Ding ◽  
Ying Long Li ◽  
Ge Zhou ◽  
...  
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Strain Rate ◽  
Deformation Mechanism ◽  
Initial Strain Rate ◽  
Lattice Diffusion ◽  
Initial Strain ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Diffusion Activation Energy

Mg-6Li-3Zn alloy sheets were prepared by melting and casting, and heavy rolling with a total reduction of 94%. The high-temperature mechanical behavior, microstructures and deformation mechanisms were investigated. The maximum elongation to failure of 300% was demonstrated at 623K and an initial strain rate of 1.67×10-3s-1. Observations by optical microscope, transmission electron microscope reveal that significant dynamic recrystallization and grain refinement occurred in banded grains at 573K and an initial strain rate of 1.67×10-3s-1, under which the subgrain contour was ambiguous and dislocation distribution was relatively uniform. It is shown by newly constructed deformation mechanism map that the high-temperature deformation mechanism in Mg-6Li-3Zn alloy sheet with banded grains at 573K and an initial strain rate of 1.67×10-3 s-1 is dislocation viscous glide controlled by lattice diffusion, the stress exponent is 3 (strain rate sensitivity exponent 0.33) and deformation activation energy is 134.8 kJ mol-1, which is the same as the lattice diffusion activation energy of magnesium.

Compression Superplasticity of Ultrahigh Carbon Steel in Electric Field

2011 ◽  
Vol 682 ◽  
pp. 177-183
Author(s):  
Ke Ke Zhang ◽  
Yun Yue ◽  
Z.L. Zhang ◽  
Ning Ma ◽  
S. Liu ◽  
...  
Keyword(s):  
Electric Field ◽  
Strain Rate ◽  
Field Intensity ◽  
Deformation Temperature ◽  
Electric Field Intensity ◽  
Rate Sensitivity ◽  
Initial Strain Rate ◽  
Carbon Steels ◽  
Initial Strain ◽  
Fine Structures

Taking 1.4%C and 1.6%C ultrahigh carbon steels (UHCSs) with ultra-fine structures developed through thermo-mechanical processing as research objects, the influences of superplastic deformation conditions and electric field on compression superplasticity were conducted without electric field and with electric field. The experimental results indicate that 1.4%C and 1.6%C UHCSs have respectively superplasticity or electro-superplasticity under the conditions of deformation temperature of 800°C, the initial strain rate of 0.75-3.75×10-4 s-1 and deformation temperature of 780 °C, the initial strain rate of 0.5-5.0×10-4 s-1 and the suitable external electric field. Its strain rate sensitivity are respectively 0.32 and 0.46.When the electric field intensity of 3 kV/cm in the manner of the specimen connected to positive terminal, the steady flow stress of 1.6%C UHCS decreases more than 10.5% as compared with electric field intensity of 0 kV/cm.

Research on the Superplastic Forming of Copper Alloy Solid-Bearing Cages Used in Railway Vehicles

2007 ◽  
Vol 551-552 ◽  
pp. 73-77 ◽  
Author(s):  
Yong Shun Yang ◽  
Guo Qing Chen ◽  
F.X. Chen
Keyword(s):  
Strain Rate ◽  
Copper Alloy ◽  
Production Efficiency ◽  
Superplastic Forming ◽  
Initial Strain Rate ◽  
Initial Strain ◽  
Uniaxial Tensile ◽  
Manufacturing Cost ◽  
Aluminum Bronze ◽  
Railway Vehicles

In this paper uniaxial tensile tests were carried out at temperature range of 650~810°C and initial strain rate range of 10-4~10-1s-1 to evaluate the superplasticity of as-casting aluminum-bronze QAl10-3-1.5 alloy. The superplastic forming technology (SPF) was adopted to produce solid-bearing cages made of aluminum-bronze QAl10-3-1.5 alloy. The results demonstrate that as-casting QAl10-3-1.5 copper alloy shows good superplasticity without prior-treatment. The maximum elongation of 545% is obtained at 790°C and initial strain rate of 1.0×10-2 s-1, while the maximum flow stress is only 12.4MPa. By using superplastic extrusion technology solid-bearing cages used in railway vehicles were obtained. As-extruded cages have good surface quality and the dimensional accuracy satisfies the design standards. Using this technology the production efficiency is greatly enhanced and the manufacturing cost is reduced, especially the expensive copper alloys are saved.

Superplastic Deformation Behavior of As-Received and Hydrogenated Ti2AlNb Alloy

2018 ◽  
Vol 385 ◽  
pp. 109-113
Author(s):  
Xi Feng Li ◽  
Guo Peng Jia ◽  
Xu Dong Cao ◽  
Jun Chen ◽  
Guo Hong Wu
Keyword(s):  
Strain Rate ◽  
Superplastic Deformation ◽  
Initial Strain Rate ◽  
Tensile Tests ◽  
Strain Rate Range ◽  
Initial Strain ◽  
Uniaxial Tensile ◽  
Hydrogen Addition ◽  
Effects Of Temperature ◽  
Superplastic Properties

In this paper, the effects of temperature and initial strain rate on the superplasticity of as-received Ti2AlNb alloy were studied by uniaxial tensile tests. Temperature from 870°C to 1030°C with an interval of 40°C and initial strain rate range of 10-2s-1to 10-4s-1were selected. The optimal superplasticity of 190.3% was obtained at 990°C with initial strain rate of 10-3s-1. The superplastic properties were deteriorated at 1030°C due to serious grain coarsening. In order to improve superplastic properties, the as-received alloy was hydrogenated with different hydrogen contents. It was found that hydrogen addition can significantly decrease flow stress and increase elongation. A higher elongation occurs at 910°C in hydrogenated alloy.

scholarly journals High Temperature Deformation Flow Of A ZK60A Magnesium Alloy After Extrusion

2015 ◽  
Vol 60 (2) ◽  
pp. 1327-1330
Author(s):  
M. Kawasaki ◽  
H.-J. Lee ◽  
M.C. Oh ◽  
B. Ahn
Keyword(s):  
High Temperature ◽  
Magnesium Alloy ◽  
Strain Rate ◽  
Flow Behavior ◽  
Rate Sensitivity ◽  
Initial Strain Rate ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Strain Rates ◽  
Testing Conditions

Abstract Flow behavior of a ZK60A magnesium alloy after continuous casting and subsequent extrusion was examined in tension at a range of strain rates of 3.0×10−6 − 1.0×10−2 s−1 at temperatures of 473-623K. The results demonstrated that the alloy exhibited a maximum elongation of ~250% at 523K when tested at an initial strain rate of 1.0×10−5 s−1 and strain rate sensitivity, m, of ~0.3-0.4 and the activation energy of ~94 kJ/mol were calculated under the testing conditions. The detailed investigation suggested that the high temperature flow of the ZK60A alloy having submicrometer grains demonstrates quasi-superplastic flow behavior controlled by a dislocation viscous glide process.

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