EXPERIMENTAL AND FEM ANALYSIS INVESTIGATION OF VARIOUS PROCESSING ROUTES OF THE PLANAR TWIST CHANNEL

International Journal of Mechanical and Production Engineering Research and Development (IJMPERD) ISSN (P): 2249–6890; ISSN (E): 2249–8001 Vol. 10, Issue 3, Jun 2020, 533–546 © TJPRC Pvt. Ltd.

EXPERIMENTAL AND FEM ANALYSIS INVESTIGATION OF VARIOUS PROCESSING ROUTES OF THE PLANAR TWIST CHANNEL ANGULAR EXTRUSION PROCESS MAHMOUD SHAMSBORHAN1*& HUSSEIN ZEKRI2 1Scholar, 2Scholar,

Department of Engineering, Mahabad Branch, Islamic Azad University, Mahabad, Iran

Department of Mechanical Engineering, University of Zakho, Zakho, Kurdistan Region, Iraq

ABSTRACT Severe Plastic Deformation (SPD) is the most appropriate top-down method for making nanocrystalline or ultrafine grained metal structures. Achieving a good distribution and higher values of equivalent plastic strain in one pass is the main parameter in severe plastic deformation processes. To solve this challenge, integrating different SPD processes is required. The planar twist channel angular extrusion process is one of the recently proposed methods of SPD as a rearrangement of two Simple Shear Extrusion (SSE) and Equal Channel Angular Pressing (ECAP) processes. In this study, Finite Element (FE) simulation of the various routes in the 2nd cycle of this method is done. Then, the micro

B2 routes have the most uniform distribution of equivalent plastic strain in the cross section area of the specimen, and B2 and A1 paths have more equivalent plastic strain values. The highest non-uniform distribution of the equivalent plastic strain is illustrated in the paths B1 and D2. The results of the micro hardness test validated FEM results. Therefore, the best options for the second cycle of the PTCAE method are the paths A1 and B2.

KEYWORDS: (PTCAE), Finite Element Analysis (FEA), Shear Strain & Severe Plastic Deformation (SPD)

Original Article

hardness test of the processed samples was performed. Finite element analysis results illustrate that the C1, C2 ,A1, and

Received: Dec 10, 2020; Accepted: Dec 30, 2020; Published: May 15, 2020; Paper Id.: IJMPERDJUN202049

1. INTRODUCTION Nano structured materials have microstructure with a grain size values in the order of 1-100nm,in one axis or direction. The base of the severe plastic deformation method is the dislocations growth, the creation of new walls of dislocations, and converting them to the new grain boundary. The make grain sizes of the material by SPD methods are in the order of 100 -1000nm; Therefore, these micro structures are named as nano structured metals [1,2].

Various investigations have been done on severe plastic deformation methods, and numerous developments have been investigated in micro-structural, analytical, and simulation fields. Several developments are related to proposing novel SPD processes for various shapes of the specimen [3-8]. A crucial factor in the SPD methods is to obtain a more equivalent plastic strain in a pass of the SPD process. Applying the effective plastic strain on various directions in only one deformation zone in only one pass is an excellent option to increase the efficiency of SPD processes. A combination of the various SPD processes can obtain this need[9,10].The planar twist channel angular extrusion process is one of the recently proposed SPD methods as are arrangement of two Simple Shear Extrusion (SSE) and Equal Channel Angular Pressing (ECAP) processes[9-13].

The Finite Element (FE) simulation has been conducted as a powerful approach in order to study the

www.tjprc.org

SCOPUS Indexed Journal

editor@tjprc.org

534

Mahmoud Shamsborhan*& Hussein Zekri

plastic deformation and strain distribution in various paths of severe plastic deformation methods [14-21].

Different paths have been described between each pass in the ECAP method based on the rotation of the sample about the longitudinal axis thereof and the rotation angle for refinement and texture evolution of the grains [2,21,22].

The rotation of the work part between consecutive ECAP passes is an optimum and straightforward technique concerning various processing paths of ECAP [23]. The use of this technique in ECAP and other SPD methods offers the possibility of deforming the materials through dissimilar strain paths due to activate various slip systems. Diverse experimental and theoretical researches were conducted to study the influence of the various paths on the shear and mechanical properties as well as microstructure development [24-29].

Generally, the micro structural dislocations homogeneity increases by increasing the cycle number in the severe plastic deformation methods, and a continuous transition from the low to the high angle grain boundaries takes place [2].

Several studies show the shear slip systems combination in the various directions for grain refining is a primary parameter, and the value of the accumulated equivalent plastic deformation is a next level important parameter [27]. In Pardis et al. paper, the Simple Shear Extrusion (SSE) as a novel SPD method is investigated in pure aluminum alloy 1050 [30].

The value and distribution of plastic deformation through four different processing routes have been investigated for the SSE method at the area of the specimen in the 2ndcycle in another study by these researchers [31].

Since, after a first pass of the PTCAE method, the specimen returns to its primary shape, repetition of the process via various paths to obtain a more accumulated plastic deformation is possible. Finite element analysis has not been investigated on the various paths of the planar twist channel angular extrusion process yet. Concerning the notability of this topic, different processing routes are defined in this investigation. Then, finite element analysis is done, and analysis with the micro hardness test results is compared.

VARIOUS PROCESSING ROUTES OF PTCAE Two simple shear extrusion and equal channel angular pressing processes are combined in the PTCAE method in one severe plastic deformation zone simultaneously. FEM analysis and Experimental studies on commercially pure copper and pure aluminum were published [9-13].

In Figure 1, the PTCAE method showed in the 3D space. So, for the 2nd pass of the PTCAE method, various routes described.

Impact Factor (JCC): 8.8746

SCOPUS Indexed Journal

NAAS Rating: 3.11

Experimental and Fem Analysis Investigation of Various Processing Routes of the Planar Twist Channel Angular Extrusion Process

535

Figure 1: ECAP, SSE Processes Combination as PTCAE Method and their Deformation Zones The first pass results of the shearing pattern of the PTCAE method are shown in Figure 2. At the mid place of the plastic deformation region, where α attains to the maximum value (the front view of the process) is the same as the SSE method. In the 2nd portion of the plastic deformation region, the specimen come back to the primary cross-section (square shape), and the sample exposed to a reverse plastic strain. Also, Figure 2 showed that the right view of the ECAP and the PTCAE processes are similar. A simultaneous combination of SSE and ECAP methods as the PTCAE method is showed in the isometric view in Figure 2.

So, two shear slip directions are available in the first cycle at the same time, where the specimen passes across the severe plastic deformation region, which leads to activation of dislocation growth in two various paths (various shear velocity produced due to the Φ and α angles difference) at the same time in just one sever plastic deformation region. So, because of the shear plastic deformation in two various planes, only one pass of the PTCAE method has more efficiency than the two passes of the SSE or ECAP methods.

Figure 3 shows the applied shear strain for the PTCAE`s first pass. The reversal shear strain is applied to the specimen in the x-axis (XZ plane) in the cross-section`s normal orientation (because ofα angle increase to the highest value at the end of the first part of the severe plastic deformation region and come back at the second part). The Φ increases the highest magnitude the same as the ECAE method in Y-axis (YZ plane), which is parallel to the extrusion axis. Shear stresses are illustrated in various directions in Figure 3.

www.tjprc.org

SCOPUS Indexed Journal

editor@tjprc.org

536

Mahmoud Shamsborhan*& Hussein Zekri

Figure 2: The First Pass of the PTCAE Method and its Shear Deformation Pattern.

Figure 3: The Effected Shear Deformation Vectors to the Specimen for the PTCAE`S First Pass.

Figure 4 is shown with the various paths in the PTCAE`s 2ndpass. Eight various routes can be described in the second pass as 90 degrees rotations step (0,90,180, and 270) around extrusion path and 180 degrees rotations step (0 and Impact Factor (JCC): 8.8746

SCOPUS Indexed Journal

NAAS Rating: 3.11

Experimental and Fem Analysis Investigation of Various Processing Routes of the Planar Twist Channel Angular Extrusion Process

537

180) about the axis normal to the extrusion axis. In contrast, in the D1, C1, B1, and A1 paths, the specimen turns about extrusion path equal to 270, 180, 90, and 0 degrees counterclockwise, respectively. Also, in the D2, C2, B2, and A2 routes, besides the explained rotation (in the previous sentence), the specimen turns equal to 180 degrees about the direction perpendicular to the extrusion path.

It should be paid attention that in the D2, C2, B2, and A2 paths, the specimen turned 1800 perpendicular to the extrusion path first, and subsequently, the specimen turns about the extrusion path.

The microstructural homogeneity of the material can be affected through these different processing paths due to different strain paths. The PTCAE method is repeated in route A1 between consecutive passes without rotating the work part, whereas the route A2 contains the reversal of the work part (rotation of the work part by 180° about a direction perpendicular to the extrusion axis). In path B1, the work part is turned 90◦ around the extrusion direction between successive cycles. In path B2, A2, and B1 routes, are combined together. Similarly, in path C1, the specimen is turned equal to180◦ about the extrusion direction among successive cycles. In path C2, A2, and C1 routes, are combined together.

The work part is turned through 270◦about the extrusion direction in route D1between successive passes. In route D2, A2 and D1 routes, are combined.

www.tjprc.org

SCOPUS Indexed Journal

editor@tjprc.org

538

Mahmoud Shamsborhan*& Hussein Zekri

Figure 4: The variouspaths in the 2ndcycle of the Planar Twist Channel Angular Extrusion Method

Figure 5 is shown with the shearing pattern results of the various PTCAE routes. Various colors are specified for the various faces of the specimen to better understand of Figure 5 .Experimental results showed that the specimen cannot recover its original shape (square) after the first pass and remain as a semi trapezius. The produced semi trapezius crosssection shape after the first pass influences the homogeneity and distribution of the plastic deformation in 2nd cycle via various routes. So, in order to understand the various routes easily, the initial cross section`s shape of the specimen in the 2nd pass is illustrated in Figure 5.

Processing path A1 applies the double reversed plastic shear deformation on the XZ plane and, also, the YZ plane similar to processing route A of SSE method and processing route A of ECAP method, respectively.

Processing path A2 applies the double reversedplastic shear deformationon the XZ plane and, also, the YZ plane similar to processing route B of SSE method and processing route A of ECAP method, respectively.

Processing path B1 applies the double reversed plastic shear deformation on the XZ plane and, also, the YZ and

Impact Factor (JCC): 8.8746

SCOPUS Indexed Journal

NAAS Rating: 3.11

Experimental and Fem Analysis Investigation of Various Processing Routes of the Planar Twist Channel Angular Extrusion Process

539

XY planes similar to processing path B of the SSE method and processing route B of ECAP method, respectively.

Processing path B2 applies the double reversed plastic shear deformation on the XZ plane and, also, the YZ and XY planes similar to processing path D of SSE method and processing route B of ECAP method, respectively.

Processing path C1 applies the double reversed plastic shear deformation on the XZ plane (that in SSE method is not available) and, also, the YZ plane similar to processing route C of ECAP method.

Processing path C2 applies the double reversed plastic shear deformation on the XZ plane (that in SSE method is not available) and, also, the YZ plane similar to processing route C of ECAP method.

Processing path D1 applies the double reversed plastic shear deformation on the XZ plane (that in SSE method is not available) and, also, the YZ and XZ planes similar to processing path B of ECAP method and 2700 rotation angle Processing path D2 applies the double reversed plastic shear deformation on the XZ plane (that in SSE method is not available) and, also, the YZ and XZ planes similar to processing path B of ECAP method and 2700 rotation angle.

Figure 5: PTCAE Processing Routes and their Shearing Pattern FEM ANALYSIS 3DFEM analysis of the second pass of the PTCAE process was done by Deform 3D V5. Further details concerning modeling, friction factor, and mesh size have been investigated in the previous studies on the FEM simulation of the PTCAE process[11,13].The die is designed, including two consecutive plastic deformation zone to reduce the computational simulation cost, which is composed of the specimen rotation between two processing routes.

Experimental Methodology Two complementary split die of the PTCAE method was manufactured. The pure aluminum specimen was experimented.

Further details of the PTCAE experimental study related to the values of the lubricant, the die dimensions, the angles Φandα, annealing conditions, and the material composition are explained in the previous research[11,13].

www.tjprc.org

SCOPUS Indexed Journal

editor@tjprc.org

540

Mahmoud Shamsborhan*& Hussein Zekri

RESULTS AND DISCUSSIONS The results of the numerical simulation Figure 6, Figure 7 and Figure 8 show the FEM results of the equivalent plastic strain distribution in the extrusion, vertical and, horizontal directions, respectively, after the two passes via various paths of the PTCAE method in the cross-section of the specimen. Also, Figure 9 shows the processing load in various routes of the PTCAE method.

Figure 6: The Equivalent Plastic Strain Distribution for various Processing Routes of the PTCAE Processed Cross-Section`S Center in the Extrusion Axis.

Figure 7: The Equivalent Plastic Strain Distribution for various Processing Routes of the PTCAE Processed Sample’s Cross-Section in the Vertical (CD) Direction.

Impact Factor (JCC): 8.8746

SCOPUS Indexed Journal

NAAS Rating: 3.11

Experimental and Fem Analysis Investigation of Various Processing Routes of the Planar Twist Channel Angular Extrusion Process

541

Figure 8: The Equivalent Plastic Strain Distribution for various Processing Paths of the PTCAE Processed Specimen`s Cross-Section in the Horizontal (AB) Direction.

The equivalent plastic strain distribution in the extrusion, vertical, and horizontal axis illustrates a similar tendency for B2 and A1 routes. However, the required load is less in path B2, because, the specimen cannot fill the exit channel of the tool completely in the first cycle [9-13], and reversal shear strain is applied to the non-filled specimen on the reverse direction in route B2 as a second pass, (same as the SSE method). The schematic form of the specimen area after the first pass is illustrated in Figure 5 to understand easily [10,12]. Similarly, C2 and C1 paths indicate a similar tendency, but the required load is less on the path C2 the same as the B2 route. The most level of the plastic strain distribution uniformity and the plastic strain values in the whole area of the cross-section simultaneously is shown in the B2, A1, C2, and C1 paths. The average plastic strain values of B2 and A1 are higher than the values of C2 and C1 paths. The path B1 illustrates the highest of the equivalent plastic strain distribution heterogeneity in the whole area of the cross-section (vertical and horizontal axis).

The length of the specimen and the distance of the first and second passes in FEM simulation of the various routes of the PTCAE method to calculate the distribution of the required force are assumed 35mm and zero respectively to simplify and reduce the numerical cost. The required force to carry out the PTCAE method of the C2 route is less than other routes, as shown in Figure 9, because there is less contact surface between the tool and the specimen in the main plastic deformation region based on the relevant specimen`s cross-section area, as shown in Figure 5. Decreased contact area resulted in less friction and required force to perform the process. Similarly, the required force to perform the D2 route is decreased. It should be noted in finite element simulation, the higher level of force is required in comparison to the actual state of the test because consecutive passes are arranged without any distance after each other, lead to creating more friction and back pressure.

www.tjprc.org

SCOPUS Indexed Journal

editor@tjprc.org

542

Mahmoud Shamsborhan*& Hussein Zekri

Figure 9: Required Force for Various Routes of the PTCAE Method Versus Punch Displacement.

EXPERIMENTAL RESULTS Figure 10 shows the values of the hardness distribution of second, first cycles of deformed specimens and annealed state in the various routes. In the vertical axis of the specimens recorded 90 HV micro hardness measurements. Excellent homogeneity distribution of the hardness is shown with no considerable difference and dissimilarity for various routes.

This hardness distribution uniformity is due to the high degree of equivalent plastic strain (approximately equals to 1.9) is applied to the specimen in the first pass of the PTCAE method [10] lead to be sufficient to saturate hardness values for commercially pure aluminum samples, and additional passes are not required through various routes. The TEM and SEM investigations confirmed the capability of the PTCAE method to produce ultrafine-grained copper and aluminum material in only one cycle of the process [12, 13].

Figure 10: The Results of the Hardness Values Distribution of Second and First Passes and also, the Annealed State in the Vertical Axis through Various Routes of the PTCAE Method.

CONCLUSIONS FEM simulations of the equivalent plastic deformation of various routes of the PTCAE process (eight routes, including A1, A2, B1, B2, C1, C2, D1 and, D2) were investigated and, Optimum route for aluminum alloy 1050 in the PTCAE process was specified. The experimental results approved the numerical results. The results showed that only one cycle of the PTCAE method is adequate to produce saturated hardness samples without required additional processing routes. In conclusion, the results illustrated that the equivalent plastic strain distribution is the same in C2, C1, B2, and A1 routes, but fewer loads are necessary for C2 and B2 routes. The highest heterogeneity of equivalent plastic strain distribution is shown

Impact Factor (JCC): 8.8746

SCOPUS Indexed Journal

NAAS Rating: 3.11

Experimental and Fem Analysis Investigation of Various Processing Routes of the Planar Twist Channel Angular Extrusion Process

543

in the B1 route in both the vertical and horizontal axis. Excellent homogeneity distribution of the hardness is shown with no considerable change for various paths of the PTCAE method. This paper confirmed that only one cycle of the PTCAE method is adequate to saturate hardness value for aluminum alloy 1050. So, the PTCAE method is a promising process to produce ultrafine-grained material in only one cycle of the method.

REFERENCES 1.

T.G. Langdon, 2007, The principles of grain refinement in equal-channel angular pressing. Materials Science and Engineering: A, 462(12) 3-11.

2.

R.Z. Valiev and T.G. Langdon, 2006, Principles of equal-channel angular pressing as a processing tool for grain refinement.

Progress in Materials Science, 51 881–981.

3.

Gupta, Ishwar, and Gaurav Saxena. "Structural analysis of rotor disc of disc brake of Baja SAE 2013 car through finite element analysis." International Journal of Automobile Engineering Research and Development (IJAuERD) Vol, 4, 1 10 (2014).

4.

M. Sh.Ghazani, A.Fardi-Ilkhchy, B.Binesh, 2018, Finite element simulation of the T-shaped ECAP processing of round samples,Journal of Materials Research Express,5(05).

5.

A. Farhoumand, S. Khoddam, P. D. Hodgson, 2012, A study of plastic deformation during axisymmetric forward spiral extrusion and its subsequent mechanical property changes, Journal of Materials Research Express, 20(08).

6.

Alavala, CHENNAKESAVA R. "FEM analysis of single point incremental forming process and validation with grid-based experimental deformation analysis." International Journal of Mechanical Engineering 5.5 (2016): 1-6.

7.

L. Olejnik, W. Chrominski, A. Rosochowski, M. Lipinska and M. Lewandowska,2014, Incremental ECAP as a novel tool for producing ultrafine grained aluminium plates, IOP Conference Series: Materials Science and Engineering, 63(01).

8.

G. Faraji, M. M. Mashhadi, A. F. Dizadji, M. Hamdi, 2012, A numerical and experimental study on tubular channel angular pressing (TCAP) process, Journal of Mechanical Science and Technology, 26(11) 3463–3468.

9.

O. Nejadseyfi, A. Shokuhfar, A. Azimi, M. Shamsborhan,2015, Improving homogeneity of ultra-fine grained/nanostructured materials produced by ECAP using a bevel-edge punch,Journal of Materials Science, 50 1513–1522.

10. Krishnaveni, J., G. Sowmya, and U. Sudhakar. "Thermal Analysis Of Cylinder Head By Using Finite Element Analysis." International Journal of Mechanical Engineering (IJME) ISSN (P) (2014): 2319-2240.

11. O. Nejadseyfi, M. Shamsborhan, A. Azimi, A. Shokuhfar,2015, The roles of crystallographic orientation, high-angle grain boundary, and indenter diameter during nano-indentation,ActaMechanica, 226 3823–3829.

12. M. Shamsborhan and A. Shokuhfar, 2014, A planar twist channel angular extrusion (PTCAE) as a novel severe plastic deformation method based on equal channel angular extrusion (ECAE) method , ProcIMechE Part C: J Mechanical Engineering Science, 228(12) 2246–2250.

13. A.Shokuhfar and M. Shamsborhan, 2014, Finite element analysis of planar twist channel angular extrusion (PTCAE) as a novel severe plastic deformation method, Journal of Mechanical Science and Technology, 28 (5) 1753-1757.

14. Madhavi, K., and K. S. Jagadish. "Split Tensile Strength of Brick Masonry." International Journal of Civil Engineering (IJCE) 6.6 (2017): 1-8.

15. M. Shamsborhan, A. Shokuhfar, O. Nejadseyfi, J. Kakemam and M. Moradi, 2015, Experimental and numerical comparison of equal channel angular extrusion (ECAE) with planar twist channel angular extrusion (PTCAE), ProcIMechE Part C: J

www.tjprc.org

SCOPUS Indexed Journal

editor@tjprc.org

544

Mahmoud Shamsborhan*& Hussein Zekri Mechanical Engineering Science, 229(16) 3059–3067.

16. M. Shamsborhan, M. Ebrahimi, 2016, Production of nanostructure copper by planar twist channel angular extrusion process,Journal of Alloys and Compounds 682 552-556.

17. M. Ebrahimi, M. Shamsborhan, 2017, Monotonic and dynamic mechanical properties of PTCAE aluminum,Journal of Alloys and Compounds, 705 28-37.

18. S. H. Hosseini, M. Sedighi, J. Mosayebnezhad, 2016, Numerical and experimental investigation of central cavity formation in aluminum during forward extrusion process,Journal of Mechanical Science and Technology, 30 (5) 1951–1956.

19. H. Jafarzadeh, K. Abrinia,2015, Numerical and experimental analyses of repetitive tube expansion and shrinking processed AZ91 magnesium alloy tubes,Journal of Mechanical Science and Technology, 29 (2) 733–738.

20. R. Kocich, L. Kunčická, A. Macháčková, 2014, Twist Channel Multi-Angular Pressing (TCMAP) as a method for increasing the efficiency of SPD, IOP Conference Series: Materials Science and Engineering, 63 (01).

21. H. Woo, K. Kee, P. Kim, 2016, Tool and process design for progressive forming of an automotive bracket part using finite element analysis,Journal of Mechanical Science and Technology, 30 (6) 2593–2599.

22. F Djavanroodi, M Ebrahimi, 2010, Effect of die channel angle, friction and back pressure in the equal channel angular pressing using 3D finite element simulation, Materials Science and Engineering: A 527 (4-5), 1230-1235.

23. F Djavanroodi, B Omranpour, M Ebrahimi, M Sedighi,2012, Designing of ECAP parameters based on strain distribution uniformity,Progress in natural science: Materials international 22 (5)452-460.

24. M Ebrahimi, F Djavanroodi, 2014, Experimental and numerical analyses of pure copper during ECFE process as a novel severe plastic deformation methodProgress in Natural Science: Materials International 24 (1)68-74.

25. E.A. El-Danaf, M.S. Soliman, A.A. Almajid, M.M. El-Rayes, 2007, Enhancement of mechanical properties and grain size refinement of commercial purity aluminum 1050 processed by ECAP. Materials Science and Engineering: A, 458 (12) 226234.

26. M. Furukawa, Y.Iwahashi, Z. Horita, M. Nemoto, T. G. Langdon, 1998, The shearing characteristics associated with equalchannel angular pressing. Materials Science and Engineering: A, 257 328–332.

27. V.M.Segal, Materials processing by simple shear,1995, Materials Science and Engineering: A,197 (2)157-164.

28. A Gholinia, PB Prangnell, MV Markushev, 2000, The effect of strain path on the development of deformation structures in severely deformed aluminium alloys processed by ECAE,ActaMaterialia 48 (5)1115-1130.

29. Y Iwahashi, Z Horita, M Nemoto, TG Langdon, 1998, The process of grain refinement in equal-channel angular pressing,Actamaterialia, 46 (9)3317-3331.

30. Y Iwahashi, Z Horita, M Nemoto, TG Langdon, 1997, An investigation of microstructural evolution during equal-channel angular pressing,Actamaterialia, 45 (11)4733-4741.

31. Y.T. Zhu, T.C. Lowe, 2000, Observations and issues on mechanisms of grain refinement during ECAP process,Materials Science and Engineering: A, 291 (1-2) 46-53.

32. L.Dupuy, E.F. Rauch, 2002, Deformation paths related to equal channel angular extrusion Materials Science and Engineering: A, 337 (1-2) 241-247.

33. M Furukawa, Z Horita, TG Langdon, 2002, Factors influencing the shearing patterns in equal-channel angular pressing,Materials Science and Engineering: A, 332 (1-2)97-109

Impact Factor (JCC): 8.8746

SCOPUS Indexed Journal

NAAS Rating: 3.11

Experimental and Fem Analysis Investigation of Various Processing Routes of the Planar Twist Channel Angular Extrusion Process

545

34. Pardis, N. and R. Ebrahimi, 2009, Deformation behavior in Simple Shear Extrusion (SSE) as a new severe plastic deformation technique, Materials Science and Engineering: A, 527 355–360.

35. Pardis, N. and R. Ebrahimi, 2010, Different processing routes for deformation via simpleshear extrusion (SSE), Materials Science and Engineering: A, 527 6153-6156.

www.tjprc.org

SCOPUS Indexed Journal

editor@tjprc.org