scholarly journals Влияние температуры деформации на эффект реализации высокой пластичности в ультрамелкозернистом сплаве Al-1.5Cu

2021 ◽  
Vol 63 (10) ◽  
pp. 1585
Author(s):  
А.М. Мавлютов ◽  
Т.С. Орлова ◽  
Э.Х. Яппарова ◽  
Н.А. Еникеев ◽  
М.Ю. Мурашкин
Keyword(s):  
Low Temperature ◽  
High Pressure Torsion ◽  
Additional Treatment ◽  
Mechanical Tension ◽  
Low Temperature Annealing ◽  
Commercially Pure ◽  
Ultrafine Grained ◽  
First Time ◽  
Temperature Side ◽  
High Ultimate Tensile Strength

For the first time the influence of temperature of mechanical tension on the plastification effect (PE) in ultrafine-grained (UFG) Al-1.5Cu (wt.%) alloy was studied. The UFG structure in the material was formed by high pressure torsion (HPT). A significant increase in the plasticity (from ~ 3% to 22%) of the UFG alloy while maintaining high ultimate tensile strength (450 MPa) was achieved by additional treatment, including low temperature annealing and subsequent small additional HPT deformation. The temperature range of the PE implementation was revealed. It was shown that decrease of the deformation temperature leads to a gradual decrease of the PE and its disappearance at –20 oC. Cu alloying led to a significant narrowing of the range of PE implementation from low temperature side compared to the UFG commercially pure Al. Possible reasons of the influence of Cu alloying on temperature dependence of the PE are discussed.

scholarly journals Hardening by Annealing and Implementation of High Ductility of Ultra-Fine Grained Aluminum: Experiment and Theory

2018 ◽  
Vol 57 (2) ◽  
pp. 224-240 ◽  
Author(s):  
T. S. Orlova ◽  
N. V. Skiba ◽  
A. M. Mavlyutov ◽  
M. Yu. Murashkin ◽  
R. Z. Valiev ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Low Temperature ◽  
High Pressure Torsion ◽  
Coarse Grained ◽  
Strengthening Effect ◽  
High Ductility ◽  
Triple Junctions ◽  
Sharp Drop ◽  
Low Temperature Annealing ◽  
First Time

Abstract The influence of low temperature annealing and subsequent deformation on microstructure, strength and ductility was investigated for the first time for high pressure torsion (HPT) processed commercially pure Al. Extremely high increases in the conventional yield stress (up to 50%) and ultimate tensile strength (up to 30%) were obtained by annealing of the ultrafine grained (UFG) samples in the range 90-200 °C for 1 h. Such increases were accompanied by a sharp drop in ductility up to 1%. Implementation of high ductility at the level of coarse-grained Al, while maintaining high strength of the HPT-processed sample was demonstrated for the first time and achieved by repeating the low temperature annealing followed by subsequent additional HPT deformation. The key role of relaxation of non-equilibrium high-angle grain boundaries (GBs) in the strengthening effect of UFG-Al by annealing is shown. Two theoretical models are suggested to explain the hardening by annealing and the implementation of high ductility in UFG structures. Within the models, plastic deformation occurs through emission of lattice dislocations from triple junctions of GBs containing pile-ups of grain-boundary dislocations, glide of the lattice dislocations across neighboring grains, their accumulation at and climb along the opposite GBs. The energy characteristics and the critical stresses of dislocation emission are determined in two different cases, for UFG Al subjected to annealing only and to annealing with subsequent additional HPT deformation. The calculated theoretical dependences of the flow stress on the plastic deformation value well fit qualitatively and quantitatively to our experimental data.

Effect of Equal Channel Angular Pressing and Annealing on Corrosion Resistance of Al-Cu Alloy

2013 ◽  
Vol 803 ◽  
pp. 226-229
Author(s):  
Da Ran Fang ◽  
Chun Liu ◽  
Feng Fang Liu
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Annealing Treatment ◽  
Coarse Grained ◽  
Nacl Solution ◽  
Angular Pressing ◽  
Cu Alloy ◽  
Low Temperature Annealing ◽  
Ultrafine Grained

Al-3.9wt.%Cu alloy was subjected to equal channel angular pressing (ECAP) and subsequent low temperature annealing treatment, and the corrosion resistance of the samples was investigated by potentiodynamic polarization measurements in 3.5% NaCl solution. The results show that the corrosion rate of the ultrafine-grained alloy increases, in comparison with the coarse-grained alloy. Meanwhile, it is noted that the corrosion resistance of the alloy subjected to ECAP can be improved by relief annealing.

scholarly journals 411 Effect of low-temperature annealing on the fatigue damage of ultrafine-grained copper

2014 ◽  
Vol 2014.67 (0) ◽  
pp. _411-1_-_411-2_
Author(s):  
Norihiro TESHIMA ◽  
Masahiro GOTO ◽  
Seungzeon HAN ◽  
Kotaro YAMAUCHI ◽  
Terutoshi YAKUSHIJI
Keyword(s):  
Low Temperature ◽  
Fatigue Damage ◽  
Low Temperature Annealing ◽  
Ultrafine Grained

scholarly journals Slippage during high-pressure torsion of commercially pure titanium and application of accumulative HPT to it

2022 ◽  
Vol 1213 (1) ◽  
pp. 012003
Author(s):  
D V Gunderov ◽  
A A Churakova ◽  
A V Sharafutdinov ◽  
V D Sitdikov ◽  
V V Astanin
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Pure Titanium ◽  
Phase Changes ◽  
Phase Content ◽  
Commercially Pure Titanium ◽  
Micro Hardness ◽  
Ω Phase ◽  
Commercially Pure ◽  
First Time

Abstract A new efficient method was used to find that in the case of high-pressure torsion of commercially pure titanium, accumulation of shear strain in Ti does not occur due to slippage of anvils. Despite this, micro-hardness increases as the number of turns n increases, and Ti structure is refined more intensively. High-pressure torsion is accompanied by a high-pressure ω-phase formation. However, the content of ω-phase changes non-monotonously with an increase in the number of turns. First, while number of turns is less than n=5, the ω-phase content reaches 50%. Upon further deformation, the ω-phase content decreases to 15% for n=20. A new accumulative high-pressure torsion method is applied to commercially pure titanium for the first time. Accumulative high-pressure torsion leads to the strongest transformation of the structure and an increase in hardness, since stronger real deformation occurs due to composition of compression and torsion strain cycles.

scholarly journals Effect of Grain Boundaries on the Electron Work Function of Ultrafine Grained Aluminum

2018 ◽  
Vol 57 (1) ◽  
pp. 110-115 ◽  
Author(s):  
T.S. Orlova ◽  
A.V. Ankudinov ◽  
A.M. Mavlyutov ◽  
N.N. Resnina
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Work Function ◽  
High Pressure Torsion ◽  
Electron Work Function ◽  
Ultrafine Grained ◽  
Average Grain Size ◽  
Different Temperatures ◽  
First Time ◽  
Specific Length

Abstract The electron work function (EWF) of ultrafine grained (UFG) aluminum structured by high pressure torsion (HPT) has been investigated. For the first time, the dependence of the EWF on the specific length of grain boundaries (or the grain size) for UFG Al has been obtained. The change of average grain size was achieved by short term annealing of HPT-processed aluminum at different temperatures from the range 90-400 °C. It has been shown that the state of grain boundaries (GBs) affects the magnitude of the EWF. It has been found that the transformation of GBs due to annealing at 90 °C from a nonequilibrium to more equilibrium state while maintaining the specific length of GBs and their average misorientation is accompanied by a decrease in average GB specific energy by 0.3 J m-2. This transition provides a sharp increase in the EWF of the UFGAl by 0.25 eV.

Effect of Equal Channel Angular Pressing and Annealing on Corrosion Resistance of Cu-Zn Alloy

2013 ◽  
Vol 706-708 ◽  
pp. 78-81 ◽  
Author(s):  
D.R. Fang ◽  
F.F. Liu ◽  
Chun Liu
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Annealing Treatment ◽  
Coarse Grained ◽  
Nacl Solution ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Ultrafine Grained ◽  
Zn Alloy

Cu-32wt.%Zn alloy was subjected to equal channel angular pressing (ECAP) and subsequent low temperature annealing treatment, and the corrosion resistance of the samples was investigated by potentiodynamic polarization measurements in 3.5% NaCl solution. The results show that the corrosion rate of the ultrafine-grained alloy decreases, in comparison with the coarse-grained alloy. Meanwhile, it is noted that the corrosion resistance of the sample subjected to ECAP can be further improved by relief annealing.

scholarly journals Retardation of Softening of Ultrafine-Grained Copper during Low Temperature Annealing under Uniaxial Tensile Stress

2012 ◽  
Vol 53 (1) ◽  
pp. 96-100 ◽  
Author(s):  
Yoji Miyajima ◽  
Takashi Aragaki ◽  
Hiroki Adachi ◽  
Toshiyuki Fujii ◽  
Susumu Onaka ◽  
...  
Keyword(s):  
Low Temperature ◽  
Tensile Stress ◽  
Uniaxial Tensile ◽  
Low Temperature Annealing ◽  
Ultrafine Grained ◽  
Uniaxial Tensile Stress

scholarly journals Ultrasonic Welding of Nickel with Coarse and Ultrafine Grained Structures

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1800
Author(s):  
Elvina R. Shayakhmetova ◽  
Mariya A. Murzinova ◽  
Ayrat A. Nazarov
Keyword(s):  
High Pressure Torsion ◽  
Ultrasonic Welding ◽  
Coarse Grained ◽  
Shear Tests ◽  
Weld Joints ◽  
Lap Shear ◽  
Ultrafine Grained ◽  
Welding Interface ◽  
Optimal Values ◽  
First Time

Solid state joints of samples of coarse-grained (CG) and ultrafine-grained (UFG) nickel have been obtained for the first time using spot ultrasonic welding (USW). The UFG structure in disk-shaped samples was processed by means of high-pressure torsion (HPT). On the basis of lap shear tests, the optimal values of the clamping force resulting in the highest values of the joint strength are determined. The microstructures in the weld joints obtained at optimal parameters of USW are characterized by scanning electron microscopy. It is shown that during ultrasonic welding of coarse-grained nickel, a thin layer with an UFG microstructure is formed near the weld surfaces. The bulks of sheets retain the CG microstructure, but a significant dislocation activity is observed in these regions. During USW of samples having an UFG initial microstructure, significant grain growth occurs. Fine grains are observed only along the welding interface. An average lap shear strength of 97 MPa was obtained by welding the UFG samples, which was approximately 40% higher than the strength of samples processed by welding coarse-grained sheets (70 MPa). It is concluded that higher strength weld joints can be obtained by using sheets with the UFG structure as compared to the CG sheets.

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