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Anomalous transformation-induced deformation in 〈1 1 0〉 textured Gum Metal / J.W. Morris Jr. in Acta materialia, Vol. 58 N° 9 (Mai 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 9 (Mai 2010) . - pp. 3271–3280 Titre : Anomalous transformation-induced deformation in 〈1 1 0〉 textured Gum Metal Type de document : texte imprimé Auteurs : J.W. Morris Jr., Auteur ; Y. Hanlumyuang, Auteur ; M. Sherburne, Auteur Année de publication : 2011 Article en page(s) : pp. 3271–3280 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Gum  Metal  Phase  transformation  Titanium  alloys Résumé : Tensile tests on single crystals of Gum Metal (Ti–36Nb–2Ta–3Zr–0.3O (wt.%)) showed, anomalously, that while a stress-induced β(bcc) → α″(orthorhombic) transformation occurred in a crystal pulled in the 〈1 1 0〉 direction, (1) no transformation was observed in crystals pulled in the 〈1 0 0〉 or 〈1 1 1〉 directions and (2) little or no transformation occurred in severely worked rods, which are polycrystals with very strong 〈1 1 0〉 texture. Analysis of the energetics of the β → α″ transformation offers straightforward explanations: (1) an α″ precipitate has zero elastic energy if it forms as a thin plate with the habit {1 1 1.5}; a 〈1 1 0〉 tensile load significantly decreases the energy of this plate; loading along 〈1 0 0〉 or 〈1 1 1〉 is less effective; (2) while worked rods have a strong 〈1 1 0〉 axial texture, the perpendicular planes are severely distorted, increasing the elastic energy of α″ and inhibiting the transformation. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S135964541000087X [article] Anomalous transformation-induced deformation in 〈1 1 0〉 textured Gum Metal [texte imprimé] / J.W. Morris Jr., Auteur ; Y. Hanlumyuang, Auteur ; M. Sherburne, Auteur . - 2011 . - pp. 3271–3280. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 9 (Mai 2010) . - pp. 3271–3280 Mots-clés : Gum  Metal  Phase  transformation  Titanium  alloys Résumé : Tensile tests on single crystals of Gum Metal (Ti–36Nb–2Ta–3Zr–0.3O (wt.%)) showed, anomalously, that while a stress-induced β(bcc) → α″(orthorhombic) transformation occurred in a crystal pulled in the 〈1 1 0〉 direction, (1) no transformation was observed in crystals pulled in the 〈1 0 0〉 or 〈1 1 1〉 directions and (2) little or no transformation occurred in severely worked rods, which are polycrystals with very strong 〈1 1 0〉 texture. Analysis of the energetics of the β → α″ transformation offers straightforward explanations: (1) an α″ precipitate has zero elastic energy if it forms as a thin plate with the habit {1 1 1.5}; a 〈1 1 0〉 tensile load significantly decreases the energy of this plate; loading along 〈1 0 0〉 or 〈1 1 1〉 is less effective; (2) while worked rods have a strong 〈1 1 0〉 axial texture, the perpendicular planes are severely distorted, increasing the elastic energy of α″ and inhibiting the transformation. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S135964541000087X