Phase transformations in Al-Ti-Mg powders consolidated by high-pressure torsion: Experiments and first-principles calculations

JOURNAL OF ALLOYS AND COMPOUNDS

卷:889

Article

Tang, Yongpeng^1,2  Murayama, Mitsuhiro^3,4  Edalati, Kaveh¹  Wang, Qing^1,5  Iikubo, Satoshi⁵  Masuda, Takahiro⁶  Higo, Yuji⁷  Tange, Yoshinori⁷  Ohishi, Yasuo⁷  Mito, Masaki²  Horita, Zenji^1,2,8,9 

[1] Kyushu Univ, Int Inst Carbon Neutral Energy Res WPI I2CNER, WPI, Fukuoka 8190395, Japan

[2] Kyushu Inst Technol, Grad Sch Engn, Kitakyushu, Fukuoka 8048550, Japan

[3] Virginia Polytech Inst & State Univ, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA

[4] Kyushu Univ, Inst Mat Chem & Engn, Kasuga, Fukuoka 8168580, Japan

[5] Kyushu Inst Technol, Dept Life & Syst Engn, Kitakyushu, Fukuoka 8080196, Japan

[6] Yokohama Natl Univ, Dept Mech Engn & Mat Sci, Yokohama, Kanagawa 2408501, Japan

[7] Japan Synchrotron Radiat Res Inst, Sayo, Hyogo 6795798, Japan

[8] Kumamoto Univ, Magnesium Res Ctr, Kumamoto 8608555, Japan

[9] Saga Univ, Synchrotron Light Applicat Ctr, Saga 8408502, Japan

关键词: Severe plastic deformation;    High-pressure torsion;    Grain refinement;    Aluminum-titanium-magnesium (Al-Ti-Mg) alloy;    High-resolution transmission electron microscopy (HRTEM);   

DOI  :  10.1016/j.jallcom.2021.161815

来源: Elsevier

【 摘 要 】

A powder mixture of Al-Ti-Mg with an equal atomic fraction was subjected to severe plastic deformation using high-pressure torsion (HPT) under 6 GPa at room temperature for full consolidation. Microstructural evolution with respect to straining and annealing was examined by X-ray diffraction (XRD) analysis and high-resolution transmission electron microscopy. The XRD analysis revealed that Ti prevails in the consolidated sample and a phase transformation occurs from alpha phase to omega phase during HPT processing while the total fraction of the omega phase increases with straining. Grain refinement to similar to 100 nm was achieved through the HPT processing for 100 revolutions as well as the formation of nanograined intermetallics such as Al3Ti, AlTi3 and TiAl. The hardness gradually increases with straining, and further increases by annealing at 573 K for 1.5 h due to the formation of an Al12Mg17 phase despite the fact that the harder omega phase was reversely-transformed to the softer alpha phase and grains were coarsened to similar to 450 nm. First-principles cal-culations show that Al and Mg elements are dissolved into the omega - Ti during HPT processing. (C) 2021 Elsevier B.V. All rights reserved.

【 授权许可】

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