An ultrafine-grained EN AW 6082 aluminum alloy was prepared by continuous serve plastic deformation (i.e., thermo-mechanical equal channel angular pressing (ECAP)-Conform process). A miniaturized tensile testing technique was used for estimating local mechanical properties with the aim to reveal the inhomogeneity of elastic and plastic properties in a workpiece volume. These inhomogeneities may appear due to the irregular shear strain distribution in a Conformed wire. Miniaturized samples for tensile testing were cut from the Conformed workpiece. Elongation of miniaturized samples was measured with a 2D digital image correlation technique as the optical extensometer. Tensile test characteristics, such as the yield strength and ultimate tensile strength, were consequently compared with results of conventional and hardness tests. The microstructure of Conformed bars was studied in the cross-section perpendicular and parallel to the extrusion direction using scanning electron microscope (SEM) and electron backscatter diffraction (EBSD) analysis. The microstructure of samples exhibits pronounced inhomogeneity, which is reflected by the hardness and tensile test results. Estimated distinctions between peripheral and central parts of the Conformed wires are probably a consequence of the significant strain differences realized in the upper and bottom wire parts.

COMTES FHT Průmyslová 995 33441 Dobřany Czech Republic

Faculty of Mathematics and Physics Charles University Ke Karlovu 3 12116 Praha 2 Czech Republic

Zobrazit více v PubMed

Valiev R., Islamgaliev R., Alexandrov I. Bulk nanostructured materials from severe plastic deformation. Prog. Mater. Sci. 2000;45:103–189. doi: 10.1016/S0079-6425(99)00007-9. DOI

Zrník J., Dobatkin S.V., Fujda M., Džugan J. Effect of Preliminary Treatment on Grain Refinement of Medium Carbon Steel Using ECAP at Increased Temperature. Mater. Sci. Forum. 2010;638:2013–2018. doi: 10.4028/www.scientific.net/MSF.638-642.2013. DOI

Estrin Y., Vinogradov A. Extreme grain refinement by severe plastic deformation: A wealth of challenging science. Acta Mater. 2013;61:782–817. doi: 10.1016/j.actamat.2012.10.038. DOI

Estrin Y., Janecek M., Raab G., Valiev R., Zi A. Severe Plastic Deformation as a Means of Producing Ultra-Fine-Grained Net-Shaped Micro Electro-Mechanical Systems Parts. Met. Mater. Trans. A. 2007;38:1906–1909. doi: 10.1007/s11661-007-9120-y. DOI

Horita Z., Fujinami T., Langdon T.G. The potential for scaling ECAP: Effect of sample size on grain refinement and mechanical properties. Mater. Sci. Eng. A. 2001;318:34–41. doi: 10.1016/S0921-5093(01)01339-9. DOI

Horita Z., Fujinami T., Nemoto M., Langdon T.G. Equal-channel angular pressing of commercial aluminum alloys: Grain refinement, thermal stability and tensile properties. Met. Mater. Trans. A. 2000;31:691–701. doi: 10.1007/s11661-000-0011-8. DOI

Xu C., Schroeder S., Berbon P.B., Langdon T.G. Principles of ECAP–Conform as a continuous process for achieving grain refinement: Application to an aluminum alloy. Acta Mater. 2010;58:1379–1386. doi: 10.1016/j.actamat.2009.10.044. DOI

Hu J., Zhang W., Fu D., Teng J., Zhang H. Improvement of the mechanical properties of Al–Mg–Si alloys with nano-scale precipitates after repetitive continuous extrusion forming and T8 tempering. J. Mater. Res. Technol. 2019;8:5950–5960. doi: 10.1016/j.jmrt.2019.09.070. DOI

Ding S., Chang C.P., Kao P. Effects of Processing Parameters on the Grain Refinement of Magnesium Alloy by Equal-Channel Angular Extrusion. Met. Mater. Trans. A. 2009;40:415–425. doi: 10.1007/s11661-008-9747-3. DOI

Seipp S., Wagner M.F.-X., Hockauf K., Schneider I., Meyer L.W., Hockauf M. Microstructure, crystallographic texture and mechanical properties of the magnesium alloy AZ31B after different routes of thermo-mechanical processing. Int. J. Plast. 2012;35:155–166. doi: 10.1016/j.ijplas.2012.03.007. DOI

Bryla K., Dutkiewicz J., Malczewski P. Grain refinement in AZ31 alloy processed by equal channel angular pressing. Arch. Mater. Sci. Eng. 2009;40:17–22.

Jin L., Lin D., Mao D., Zeng X., Chen B., Ding W. Microstructure evolution of AZ31 Mg alloy during equal channel angular extrusion. Mater. Sci. Eng. A. 2006;423:247–252. doi: 10.1016/j.msea.2006.02.045. DOI

Vinogradov A., Estrin Y. Analytical and numerical approaches to modelling severe plastic deformation. Prog. Mater. Sci. 2018;95:172–242. doi: 10.1016/j.pmatsci.2018.02.001. DOI

Hodek J., Kubina T. FEM Model and Experimental Production of Titanium Rods Using Conform Machine. TANGER; Ostrava, Czech Republic: 2013. pp. 347–351.

Fakhretdinova E., Raab G., Ryzhikov O., Valiev R.Z. Processing ultrafine-grained Aluminum alloy using Multi-ECAP-Conform technique. IOP Conf. Ser. Mater. Sci. Eng. 2014;63:012037. doi: 10.1088/1757-899X/63/1/012037. DOI

Murashkin M., Sabirov I., Prosvirnin D., Ovid’Ko I., Terentiev V., Valiev R.Z., Dobatkin S. Fatigue Behavior of an Ultrafine-Grained Al-Mg-Si Alloy Processed by High-Pressure Torsion. Metals. 2015;5:578–590. doi: 10.3390/met5020578. DOI

Raab G.J., Valiev R.Z., Lowe T.C., Zhu Y. Continuous processing of ultrafine grained Al by ECAP–Conform. Mater. Sci. Eng. A. 2004;382:30–34. doi: 10.1016/j.msea.2004.04.021. DOI

Xu C., Száraz Z., Trojanová Z., Lukáč P., Langdon T.G. Evaluating plastic anisotropy in two aluminum alloys processed by equal-channel angular pressing. Mater. Sci. Eng. A. 2008;497:206–211. doi: 10.1016/j.msea.2008.06.045. DOI

Trojanová Z., Džugan J., Halmešová K., Németh G., Minárik P., Lukáč P., Bohlen J. Influence of Accumulative Roll Bonding on the Texture and Tensile Properties of an AZ31 Magnesium Alloy Sheets. Materials. 2018;11:73. doi: 10.3390/ma11010073. PubMed DOI PMC

Máthis K., Köver M., Stráská J., Trojanová Z., Džugan J., Halmešová K. Micro-Tensile Behavior of Mg-Al-Zn Alloy Processed by Equal Channel Angular Pressing (ECAP) Materials. 2018;11:1644. doi: 10.3390/ma11091644. PubMed DOI PMC

Trojanová Z., Halmešová K., Džugan J., Palček P., Minárik P., Lukáč P. Influence of strain rate on deformation behaviour of an AX52 alloy processed by equal channel angular pressing (ECAP) Lett. Mater. 2018;8:517–523. doi: 10.22226/2410-3535-2018-4-517-523. DOI

Kubina T., Dlouhy J., Kövér M., Hodek J. Study of Thermal Stability of Ultra Fine-Grained Commercially Pure Titanium Wire Prepared in Conform Equipment. Mater. Sci. Forum. 2014;782:415–420. doi: 10.4028/www.scientific.net/MSF.782.415. DOI

Jirková H., Rubešová K., Konopík P., Opatová K. Effect of the Parameters of Semi-Solid Processing on the Elimination of Sharp-Edged Primary Chromium Carbides from Tool Steel. Metals. 2018;8:713. doi: 10.3390/met8090713. DOI

Džugan J., Konopík P., Trojanová Z., Procházka R. SPD Processed Materials Mechanical Properties Determination with the Use of Miniature Specimens. Mater. Sci. Forum. 2016;879:471–476. doi: 10.4028/www.scientific.net/MSF.879.471. DOI

Konopík P., Džugan J., Procházka R. Evaluation of Local Mechanical Properties of Steel Weld by Miniature Testing Technique. MS and T; Rolla, MO, USA: 2013. pp. 2404–2411.

Džugan J., Konopík P., Procházka R. Micro-Tensile test technique development and application to mechanical property determination. Small Spec. Test Tech. 2014;6:12–30. doi: 10.1520/STP157620140022. DOI

Maleček L., Palán J., Nacházel J., Dlouhy J. Influence of rotary swaging and subsequent age hardening on properties of EN AW 6082 aluminium alloy. IOP Conf. Ser. Mater. Sci. Eng. 2017;179:12049. doi: 10.1088/1757-899X/179/1/012049. DOI

Salehi M.S., Anjabin N., Kim H.S. Study of Geometrically Necessary Dislocations of a Partially Recrystallized Aluminum Alloy Using 2D EBSD. Microsc. Microanal. 2019;25:656–663. doi: 10.1017/S1431927619000382. PubMed DOI

Derakhshan J.F., Parsa M., Jafarian H. Microstructure and mechanical properties variations of pure aluminum subjected to one pass of ECAP-Conform process. Mater. Sci. Eng. A. 2019;747:120–129. doi: 10.1016/j.msea.2019.01.058. DOI

Dmitriev A.I., Nikonov A.Y., Shugurov A.R., Panin A.V. The Role of Grain Boundaries in Rotational Deformation in Polycrystalline Titanium under Scratch Testing. Phys. Mesomech. 2019;22:365–374. doi: 10.1134/S1029959919050035. DOI

De Castro V., Leguey T., Muñoz A., Monge M., Pareja R. Relationship between hardness and tensile tests in titanium reinforced with yttria nanoparticles. Mater. Sci. Eng. A. 2005;400:345–348. doi: 10.1016/j.msea.2005.03.070. DOI

Ashby M.F. The deformation of plastically non-homogeneous materials. Philos. Mag. 1970;21:399–424. doi: 10.1080/14786437008238426. DOI