Effect of cross-sectional area reduction rate and alloy composition on the formation of <001>-fiber texture in Ti-Mo-Al-Zr alloy wire

¹ Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, 4259, Nagatsutacho, Midori-ku, Yokohama 226-8503, Japan
² Laboratory for Future Interdisciplinary Research of Science and Technology, Institute of Innovative Research, Tokyo Institute of Technology, 4259, Nagatsutacho, Midori-ku, Yokohama 226-8503, Japan
³ Tokyo Institute of Technology, 4259, Nagatsutacho, Midori-ku, Yokohama 226-8503, Japan

^* Corresponding author E-mail: shinohara.y.aa@m.titech.ac.jp

Abstract

Texture formation in Ti-7Mo-8Al-6Zr cold-groove-rolled alloy wires was investigated and compared to that of Ti-5.5Mo-8Al-6Zr. Irregularly textured <001>-fiber was formed in Ti-5.5Mo-8Al-6Zr. The Ti-7Mo-8Al-6Zr cold-groove-rolled wire mainly composed of the β phase though α″ martensite was induced by cold-groove-rolling in the Ti-5.5Mo-8Al-6Zr alloy. From the TEM observations of the severely deformed cold-rolled sheet, α″ martensite was assumed to be induced during cold-groove-rolling and trace α″ was assumed to be retained after cold-groove-rolling. This texture is common in bcc metals and corresponds to the <010>_α″ -fiber which is formed in the Ti-5.5Mo-8Al-6Zr alloy when the lattice correspondence between β and α″ is considered. On the other hand, the <001>-fiber was strongly developed in the cold-groove-rolled wire with a reduced cross sectional area of 98% following solution treatment, while this texture was not observed in the specimen with a 60% reduced cross sectional area. The texture formed in solution-treated Ti-7Mo-8Al-6Zr alloy wire was similar to that of the Ti-5.5Mo-8Al-6Zr alloy, although the dominant phase in the cold-groove-rolled specimen differed.