Abstract
Cylindrical samples of CP Titanium (Grade 2) were deformed by one, two and three passes of equal channel angular pressing (ECAP) each at temperatures 77, 300 and 575 K, respectively. The microstructure of samples processed at 77 K shows retardation of recrystallisation, high density of dislocations and deformation twins, diffuse and obscure grain boundaries compare to microstructure of samples processed at room and high temperature, where recrystallised ultrafine equiaxed grains are observed. Mechanical properties for all structural states of Ti were studied by microhardness measurements at 300 K and uniaxial compression at temperatures 300, 170, 77 and 4.2 K. Higher levels of ECAP deformation (more passes of ECAP) lead to higher values of strength and hardness at all studied temperatures. Decrease of ECAP temperature leads to increase of strength characteristics in all cases. Influence of ECAP and compression temperatures on possible changes of deformation mechanism are discussed.
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Nam WJ, Lee YB, Dong DH (2004) Ultrafine grained bulk 5083 Al alloy produced by cryogenic rolling process. Mater Sci Forum 449–452:141–144
Moskalenko VA, Smirnov AR, Moskalenko AV (2009) Nanocrystalline titanium produced by the cryomechanical method: microstructure and mechanical properties. Low Temp Phys 35:1160–1164
Yin J, Lu J, Zhang P (2004) Nanostructural formation of fine grained aluminum alloy by severe plastic deformation at cryogenic temperature. J Mater Sci 39:2851–2854. doi:10.1023/B:JMSC.0000021463.83899.b3
Kon’kova TN, Mironov SY, Korznikov AV (2010) Severe cryogenic deformation of copper. Phys Metal Metallogr 109:171–176
Podolskiy AV, Mangler C, Schafler E, Tabachnikova ED, Zehetbauer MJ (2013) Microstructure and mechanical properties of high purity nanostructured titanium processed by high pressure torsion at temperatures 300 and 77 K. J Mater Sci 48:4689–4697. doi:10.1007/s10853-013-7276-y
Chen YJ, Roven HJ, Gireesh SS, Skaret P, Hjelen J (2011) Quantitative study of grain refinement in Al–Mg alloy processed by equal channel angular pressing at cryogenic temperature. Mater Lett 65:3472–3475
Fritsch S, Scholze M, Wagner MF-X (2012) Cryogenic forming of AA7075 by equal-channel angular pressing. Mater Werkst 43:561–566
Kutniy KV, Volchok OI, Kislyak IF, Tikhonovsky MA, Storozhilov GE (2011) Obtaining of pure nanostructured titanium for medicine by severe deformation at cryogenic temperatures. Mater. Werkst. 42:114–117
Lapovok R, Molotnikov A, Levin Y, Bandaranayake A, Estrin Y (2012) Machining of course grained and ultrafine grained titanium. J Mater Sci 47:4589–4594. doi:10.1007/s10853-012-6320-7
Segal VM (1995) Materials processing by simple shear. Mater Sci Eng A 197:157–164
Lapovok R, Tomus D, Muddle BC (2008) Low-temperature compaction of Ti–6Al–4V powder using equal channel angular extrusion with back-pressure. Mater Sci Eng A 490:171–180
Lapovok R, Estrin Y, Popov MV, Langdon TG (2008) Enhanced superplasticity in a magnesium alloy processed by equal-channel angular pressing with a back-pressure. Adv Eng Mater 10:429–433
Kovaleva VN, Moskalenko VA, Natsik VD (1994) Barrier parameters and statistics controlling the plasticity of Ti–O solid solutions in the temperature range 20–550 K. Phil Mag A 70:423–438
Evans A, Rawlings R (1969) The thermally activated deformation of crystalline materials. Phys Stat Solidi 34:9–31
Pustovalov VV (2008) Serrated deformation of metals and alloys at low temperatures. Low Temp Phys 34:683–723
Tabachnikova ED, Bengus VZ, Podolskiy AV, Smirnov SN, Gunderov DV, Valiev RZ (2006) Low temperature mechanical properties of different commercial purity nanostructured titanium processed by ECA pressing. Mater Sci Forum 503–504:633–638
Li L, Anderson PM, Lee MG, Bitzck E, Derlet P, Swygenhoven HV (2009) The stress-strain response of nanocrystalline metals: a quantized crystal plasticity approach. Acta Mater 57:812–822
Tabachnikova ED, Podolskiy AV, Smirnov SN, Psaruk IA, Bengus VZ, Li H, Li L, Chu H, Liao PK (2012) Thermal activation plasticity of nanocrystalline Ni-18.75 at.% Fe alloy in temperature range 4.2–350 K. Low Temp Phys 38:239–247
Kocks F, Argon AS, Ashby MF (1975) Thermodynamics and kinetics of slip. Progr Mater Sci 19:1–288
Zehetbauer MJ, Zhu YT (eds) (2009) Bulk nanostructured materials. Wiley, Weinheim
Wang Y, Ma E (2004) Three strategies to achieve uniform tensile deformation in a nanostructured metal. Acta Mater 52:1699–1709
Zwicker U (1974) Titan und Titanlegierungen. Springer, Berlin
Meyers MA, Mishra A, Benson DJ (2006) Mechanical properties of nanocrystalline materials. Progr Mater Sci 51:427–556
Asaro J, Suresh S (2005) Mechanistic models for the activation volume and rate sensitivity in metals with nanocrystalline grains and nano-scale twins. Acta Mater 53:3369–3382
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Podolskiy, A.V., Ng, H.P., Psaruk, I.A. et al. Cryogenic equal channel angular pressing of commercially pure titanium: microstructure and properties. J Mater Sci 49, 6803–6812 (2014). https://doi.org/10.1007/s10853-014-8382-1
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DOI: https://doi.org/10.1007/s10853-014-8382-1