{"title":"The Effect of Deformation Activation Volume, Strain Rate Sensitivity and Processing Temperature of Grain Size Variants","authors":"P. B. Sob, A. A. Alugongo, T. B. Tengen","volume":107,"journal":"International Journal of Mechanical and Mechatronics Engineering","pagesStart":1928,"pagesEnd":1932,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/10002703","abstract":"<p>The activation volume of 6082T6 aluminum is<br \/>\r\ninvestigated at different temperatures for grain size variants. The<br \/>\r\ndeformation activation volume was computed on the basis of the<br \/>\r\nrelationship between the Boltzmann&rsquo;s constant k, the testing<br \/>\r\ntemperatures, the material strain rate sensitivity and the material yield<br \/>\r\nstress grain size variants. The material strain rate sensitivity is<br \/>\r\ncomputed as a function of yield stress and strain rate grain size<br \/>\r\nvariants. The effect of the material strain rate sensitivity and the<br \/>\r\ndeformation activation volume of 6082T6 aluminum at different<br \/>\r\ntemperatures of 3-D grain are discussed. It is shown that the strain rate sensitivities and activation volume<br \/>\r\nare negative for the grain size variants during the deformation of<br \/>\r\nnanostructured materials. It is also observed that the activation<br \/>\r\nvolume vary in different ways with the equivalent radius, semi minor<br \/>\r\naxis radius, semi major axis radius and major axis radius. From the<br \/>\r\nobtained results it is shown that the variation of activation volume<br \/>\r\nincrease and decrease with the testing temperature. It was revealed<br \/>\r\nthat, increase in strain rate sensitivity led to decrease in activation<br \/>\r\nvolume whereas increase in activation volume led to decrease in<br \/>\r\nstrain rate sensitivity.<\/p>\r\n","references":"[1] Segal, V. M. 2005.Deformation mode and plastic flow in ultra-fine\r\ngrained metals. Materials Science and Engineering A 406(2005)205-\r\n216.\r\n[2] Laszlo, S. Toth & Chengfan Gu.Ultrafine grain metals by severe plastic\r\ndeformation. Material Characterization 92(2014) 1-14.\r\n[3] Cuenot, S. & Fretigny, C. & Demoustier, S. & NYSTEN, B. 2004.\r\nSurface tension effect on the mechanical properties by atomic\r\nmicroscopy. The American Physical Society 69 (16):1-5, 20.\r\n[4] Wang, Z. J. & Shan, Q. J. & Sun, L. J. & MA, E. 2012. Sample size\r\neffects on the large strain bursts in submicron aluminum pillars. Applied\r\nPhysics Letters 100, 071906.\r\n[5] Zhou, C. & Beyerlein, I. J. & LESAR, R. 2011. Plastic deformation\r\nmechanisms of fcc single crystals at small scales. Acta Materaillia 59\r\n(20), 7673-7682.\r\n[6] Zhu. T, & LI. J, & Samanta. A, & Leache. A, & Gall, K. 2008.\r\nTemperature and strain rate dependence of surface dislocation\r\nnucleation. Physical Review Letters 100 (2), 025502.\r\n[7] Anton, S. & Brane, S. & Mateyz, F. 2009. Determination of the strainrate\r\nsensitivity and the activation energy of deformation in the\r\nsuperplastic aluminium alloy Al-Mg-Mn-Sc. RMZ \u2013 Materials and\r\nGeoenvironment, Vol. 56, No. 4, pp. 389\u2013399, 2009.\r\n[8] Sabirov, I. & Barnett, M. R. & Estrin, Y. & Hodgson, P. D. 2009. The\r\neffect of strain rate on the deformation mechanisms and the strain rate\r\nsensitivity of an ultra-fine-grained Al alloy. Scripta Materialia 61 (2009)\r\n181\u2013184.\r\n[9] Brad, L. B. &Thomas, B. C. &Morris, F. D. 2007. The Strain-Rate\r\nSensitivity of High-Strength High-Toughness Steels. Sanddia Report\r\nSand 2007-0036.\r\n[10] Kumar, R. & Sharma, G. & Kumar, M. 2013. Effect of size and shape on\r\nthe vibrational and thermodynamics properties of nanomaterials. Journal\r\nof thermodynamics Vol. pp 5.\r\n[11] Lee, W. S. & Lin, C. F. &Chen, T. H. & Hwang, H. H. 2008. Effects of\r\nstrain rate and temperature on mechanical behavior of Ti\u201315Mo\u20135Zr\u2013\r\n3Al alloy. J Mech Behav Biomed Mater 2008;1(4):336\u201344.\r\n[12] Chiou, S. T. & Tsai, H. L. & Lee, W. S. 2009. Impact mechanical\r\nresponse and microstructural evolution of Ti alloy under various\r\ntemperatures. J Mater Process Technol2009; 209(5):2282\u201394.\r\n[13] Guisbiers, G. 2010. Size dependent materials properties towards a\r\nuniversal equation. Nanoscale Research Letters, Vol. 5, No.7, pp. 1132-\r\n1136.\r\n[14] Zhang, Z. & Lii, X. X. & Jiang, Q. 1999. Finite size effect on melting\r\nenthalpy and melting entropy of nanocrystals. Physical B Vol. 270, No.\r\n3-4, pp. 249-254.\r\n[15] Gunderov, D. V. & Maksutova, G. & Churakova, A. & lukyanov, A. &\r\nKreitcberg, A. & Raab, G. I. & Sabirov, A. I. & Prokoshkin, S. 20015.\r\nStrain rate sensitivity and activation volume of coarse-grained and\r\nultrafine-grained TiNi alloys. ScriptaMateriallia 102 (2015) 99-102.\r\n[16] Zhao, M. & Jiang, Q. 2006. Reverse hall-petch relationship of metals in\r\nnanometer size. Emerging Technologies-Nanoelectronics, IEEE\r\nConference on Vol. pp 472-474, (10-13 Jan. 2006.\r\n[17] Tengen, T. B. & Iwankiewicz, R. 2009. Modelling of the grain size\r\nprobability distribution in polycrystalline. Composite Structures\r\n91(2009) 461-466\r\n[18] Tengen, T. B. 2008.Analysis of Characteristic of Random\r\nMicrostructures of Nanomaterials. PhD. Thesis. Witwatersrand\r\nJohannesburg.\r\n[19] Sob, P. B. & Alugongo, A. A. & Tengen, T. B. 2015. Determination of\r\nstrain rate sensitivity (SRS) for grain size variants on nanocrystalline\r\nmaterials produced by ARB and equal channel angular pressing\r\n(ECAP). 17th International Conference on Advanced Materials and\r\nNanotechnology (ICAMN 2015), World Academy of Science,\r\nEngineering and Technology, Bangkok, Thailand, paper number\r\n15TH12000585.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 107, 2015"}