Static and Cyclic Deformation of Commercially Pure Al Processed by Equal-Channel Angular Pressing Using Two Routes

2010 ◽  
Vol 667-669 ◽  
pp. 833-838
Author(s):  
Mahmoud S. Soliman ◽  
Ehab A. El-Danaf ◽  
Abdulhakim A. Almajid
Keyword(s):  
Cyclic Deformation ◽  
Extrusion Direction ◽  
Shear Plane ◽  
Coarse Grained ◽  
Processing Route ◽  
Angular Pressing ◽  
Commercially Pure ◽  
Tension And Compression ◽  
Internal Angle ◽  
Number Of Passes

In the present investigation, annealed billets of commercially pure Al (1050) with coarse-grained microstructure of 0.6 mm were ECAPed through a die with an internal angle of 90o using two routes A and BC. The samples were processed up to four passes using both routes. The change in the processing route results in the change of the shear plane, and consequently the change in the produced microstructure. The microstructure study was conducted on the extrusion direction and the shear plane. The cell size, misoriention and the fraction of high angle boundaries were determined by using electron back scattered diffraction (EBSD). A study of mechanical behavior was conducted by cutting tensile and compression specimens from the ECAPed specimen in the extrusion direction to study the effect of processing route and the number of passes on the deformation characteristics. Enhanced strength was observed but with anisotropic behavior between tension and compression. Cyclic deformation under load control (HSF) was also performed and the S-N curves were established as a function of number of passes and processing route. The fractography of fractured tensile specimens was also investigated.

scholarly journals Microstructure Evaluation Study of Al5083 Alloy Using EBSD Technique after Processing with Different ECAP Processes and Temperatures

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 862
Author(s):  
Muneer Baig ◽  
Asiful H. Seikh ◽  
Ateekh Ur Rehman ◽  
Jabair A. Mohammed ◽  
Faraz Hussain Hashmi ◽  
...  
Keyword(s):  
Grain Refinement ◽  
Evaluation Study ◽  
Coarse Grained ◽  
Angular Pressing ◽  
Microstructure Evaluation ◽  
Microstructural Evaluation ◽  
Higher Temperature ◽  
Ebsd Technique ◽  
Number Of Passes ◽  
Positive Effect

The temperature effects on the microstructural evolution of a coarse-grained Al5083 alloy during equal channel angular pressing (ECAP), were studied at ambient and high temperatures. The microstructural evaluation was done using an EBSD (electron backscattering diffraction) process. The grain refinement occurred as the number of passes increased, which had a positive effect on its strength. Additionally, increasing the pressing temperature leads to a decrease in the new grain’s formation and an increase in the normal grain size in the third pass. This can be ascribed to the unwinding of strain similarity between the grains because of the continuous activity of dynamic recuperation and the grain limit sliding occurring at a higher temperature. The attainment of grain refinement is examined exhaustively in this study.

Strengthening Behavior of Bulk Ultra Fine Grained Aluminum Alloys

2012 ◽  
Vol 710 ◽  
pp. 241-246 ◽  
Author(s):  
R. Manna ◽  
N.K. Mukhopadhyay ◽  
G.V.S. Sastry
Keyword(s):  
Aluminum Alloys ◽  
Grain Refinement ◽  
Cell Formation ◽  
Dislocation Cell ◽  
Equivalent Strain ◽  
Alloying Elements ◽  
Coarse Grained ◽  
Strengthening Effect ◽  
Angular Pressing ◽  
Number Of Passes

Billets of aluminum and aluminum alloys have been deformed at room temperature using a die having equal channels of 10 mm diameter intersecting at an inner angle of 120° and outer arc of 60° by equal channel angular pressing (ECAP) to ultra fine grain (UFG) size level, adopting route Bc. Mechanical properties were evaluated by tensile testing and microhardness measurement. Effects of alloying elements on strengthening were explored. The strengths increase rapidly at first few passes and then reach to a saturation level. The improvement in strength at initial passes of ECAP is due to work hardening and subgrain or dislocation cell formation. However, strengthening at large number of passes is due to the grain refinement alone. The rate of strengthening as a function equivalent strain decreases to a minimum. The strengthening level of bulk UFG alloys is about 3.5 to 4.5 times to that of starting materials. The major cause of strengthening is grain refinement apart from solute strengthening. Among Mg, Zn and Ag alloying elements, the strengthening effect is highest for Mg and lowest for Ag. Ductility is regained without affecting the strength after sufficient number of passes when microstructure becomes equiaxed and ultra-fine in size. However, ductility of UFG Al alloys is lower than that of their coarse grained counterpart.

Low Temperature Mechanical Properties of Different Commercial Purity Nanostructured Titanium Processed by ECA Pressing

2006 ◽  
Vol 503-504 ◽  
pp. 633-638 ◽  
Author(s):  
Elena D. Tabachnikova ◽  
Vladimir Z. Bengus ◽  
Aleksey V. Podolskiy ◽  
S.N. Smirnov ◽  
Dmitriy Gunderov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Structural State ◽  
Mechanical Characteristics ◽  
Coarse Grained ◽  
Commercial Purity ◽  
Nanostructured Titanium ◽  
Fine Grained ◽  
Angular Pressing ◽  
Tension And Compression

Low temperature mechanical characteristics under quasistatic uniaxial tension and compression have been studied of ultra fine-grained structural state of polycrystalline titanium – nanostructured titanium, processed by the equal channel angular pressing (ECAP). Values of the yield stress and the uniform plasticity at 300, 77, and 4.2 K for nanostructured (NS) and polycrystalline coarse-grained (CG) titanium of different commercial purity have been compared.

Influence of Dynamic Recrystallisation on Texture Formation in ECAP deformed Nickel

2007 ◽  
Vol 558-559 ◽  
pp. 575-580 ◽  
Author(s):  
Werner Skrotzki ◽  
Burghardt Klöden ◽  
I. Hünsche ◽  
Robert Chulist ◽  
Satyam Suwas ◽  
...  
Keyword(s):  
Orientation Imaging Microscopy ◽  
High Energy ◽  
Texture Gradient ◽  
Texture Formation ◽  
Microstructure Formation ◽  
Fcc Metals ◽  
Orientation Imaging ◽  
Angular Pressing ◽  
Dynamic Recrystallisation ◽  
Number Of Passes

3N nickel has been deformed by equal channel angular pressing (ECAP) at 400°C up to 3 passes using route A. The texture with respect to position in the deformed billet, i.e. from top to bottom, has been measured with high-energy synchrotron radiation. It is characterized by texture components typical for simple shear in the intersection plane of the square-shaped 90° bent channel. Besides, an oblique cube component is observed. Orientation imaging microscopy clearly shows that this component is due to partial recrystallization. Intensities of the texture components as well as deviations from their ideal shear positions vary from the top to the bottom of the billet and with the number of passes. The change of the intensity of texture components and the texture gradient investigated is discussed. Special emphasis is put on the influence of dynamic recrystallization on texture and microstructure formation during ECAP of fcc metals.

Effect of Equal-Channel Angular Pressing (ECAP) on Creep in Aluminium Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 2904-2909 ◽  
Author(s):  
Vàclav Sklenička ◽  
Jiří Dvořák ◽  
Marie Kvapilová ◽  
Milan Svoboda ◽  
Petr Král ◽  
...  
Keyword(s):  
Equal Channel Angular Pressing ◽  
Aluminium Alloys ◽  
Creep Resistance ◽  
Room Temperature ◽  
Creep Behaviour ◽  
Coarse Grained ◽  
Pure Aluminium ◽  
Creep Tests ◽  
Angular Pressing ◽  
Compression Creep

This paper examines the effect of equal-channel angular pressing (ECAP) on creep behaviour of pure aluminium, binary Al-0.2wt.%Sc alloy and ternary Al-3wt.%Mg-0.2wt.%Sc alloy. The ECAP was conducted at room temperature with a die that had a 90° angle between the channels and 8 repetitive ECAP passes followed route BC. Constant stress compression creep tests were performed at 473 K and stresses ranging between 16 to 80 MPa on ECAP materials and, for comparison purposes, on the initial coarse-grained materials. The results showed that the creep resistance of the ECAP processed Al-Sc and Al-Mg-Sc alloys was markedly deteriorated with respect to unpressed coarse-grained materials.

Improvement of Strength of Mg-12Gd-3Y-0.5Zr Alloys Processed by Combination of ECAP and Extrusion

2011 ◽  
Vol 682 ◽  
pp. 211-216
Author(s):  
Rong Zhu ◽  
Jin Qiang Liu ◽  
Jing Tao Wang ◽  
Ping Huang ◽  
Yan Jun Wu ◽  
...  
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Grain Boundary ◽  
Low Temperatures ◽  
Basal Slip ◽  
Extrusion Direction ◽  
Strengthening Mechanisms ◽  
Step Process ◽  
Angular Pressing ◽  
Peak Intensity

Equal channel angular pressing (ECAP) has been used to refine the grain size of Mg-12Gd-3Y-0.5Zr billet at about 400°C because it lacks sufficient ductility at low temperatures. However, <0001> peak intensity is oriented about 50º from the extrusion direction, which facilitates the basal slip, and decreases the yield strength. We have employed conventional extrusion at 300°C following ECAP to modify the texture in hard orientation. This two-step process makes use of two strengthening mechanisms a) grain boundary strengthening due to small grain size, and (b) texture strengthening due to grains in hard orientation. The samples processed by the two-step show the yield and ultimate strength to 283 and 308 MPa, respectively. Moreover, the activation of <c+a> slip and fine grains resulted from the ECAP helped to maintain a good ductility even after significant straining from conventional extrusion.

Characterization of Flow Stress for Commercially Pure Titanium Subjected to Electrically-Assisted Deformation

2013 ◽  
Author(s):  
James Magargee ◽  
Fabrice Morestin ◽  
Jian Cao
Keyword(s):  
Flow Stress ◽  
Heating Temperature ◽  
Pure Titanium ◽  
Constitutive Models ◽  
Plastic Behavior ◽  
Commercially Pure Titanium ◽  
Coupled Models ◽  
Commercially Pure ◽  
Electrically Assisted ◽  
Tension And Compression

Uniaxial tension tests were conducted on thin commercially pure titanium sheets subjected to electrically-assisted deformation using a new experimental setup to decouple thermal-mechanical and possible electroplastic behavior. The observed absence of stress reductions for specimens air-cooled to near room temperature motivated the need to reevaluate the role of temperature on modeling the plastic behavior of metals subjected to electrically-assisted deformation, an item that is often overlooked when invoking electroplasticity theory. As a result, two empirical constitutive models, a modified-Hollomon and the Johnson-Cook models of plastic flow stress, were used to predict the magnitude of stress reductions caused by the application of constant DC current and the associated Joule heating temperature increase during electrically-assisted tension experiments. Results show that the thermal-mechanical coupled models can effectively predict the mechanical behavior of commercially pure titanium in electrically-assisted tension and compression experiments.

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.

Texture Gradient in ECAP Silver Measured by Synchrotron Radiation

2005 ◽  
Vol 495-497 ◽  
pp. 821-826 ◽  
Author(s):  
Werner Skrotzki ◽  
N. Scheerbaum ◽  
C.G. Oertel ◽  
Heinz Günter Brokmeier ◽  
Satyam Suwas ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Neutron Diffraction ◽  
Room Temperature ◽  
Extrusion Direction ◽  
High Energy ◽  
Texture Gradient ◽  
Fcc Metals ◽  
Local Texture ◽  
Angular Pressing ◽  
Global And Local

Silver of 3N purity was deformed at room temperature by equal channel angular pressing (ECAP) using three passes of route A. The global and local texture were investigated by neutron diffraction and high-energy synchrotron radiation, respectively. The texture is characterized by typical simple shear components of fcc metals which differently deviate from their ideal positions. Local texture measurements reveal that the intensity and inclination of the texture components with respect to the extrusion direction depend on the distance from the top of the extruded bar and change from pass to pass. Reasons for the texture gradient are discussed. The texture of silver is compared with that of copper having a higher stacking fault energy.

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