Correlation of Alpha Phase and Its Texture Stability in Heat-Treated Ti-6.5Al-4.4V-0.15Fe Alloy

Gupta, A and Shankar, G and Mahadule, D and Khatirkar, RK (2023) Correlation of Alpha Phase and Its Texture Stability in Heat-Treated Ti-6.5Al-4.4V-0.15Fe Alloy. In: Journal of Materials Engineering and Performance .

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Abstract

In the present work, microstructure, texture, and mechanical properties were investigated for the heat-treated two-phase (α + β) titanium alloy samples. Ti-6.5%Al-4.4%V-0.15%Fe alloy samples were heated to three different temperatures (850, 930, and 1066 °C) followed by oil quenching (OQ), air cooling (AC), and furnace cooling (FC), respectively. Primary alpha (αP) and secondary alpha (αS) were dominant in the microstructure, when heat-treated below βT (beta-transus) temperature, i.e., 850 and 930 °C. Widmanstatten α (αWS) and basket-weave α (αBW) were dominant features in the microstructure of the samples heat-treated above the βT, i.e., 1066 °C. Formation of the martensite (α′) was observed in all three cases of the OQ samples. Differences in the volume fraction of the αP and αS were observed in the microstructure due to differences in the heating temperature and cooling rate. Texture developments after heat treatment were measured through the electron back-scatter diffraction (EBSD) technique. Variation in the texture intensity values was observed in the samples heat-treated below the βT which shows the dependence of the texture on the volume fraction of αP and αS. Similarly, formation of the big α colonies causes the changes in the texture when heat-treated above the βT. Grain partitioning of αP and αS in 850 and 930 °C-OQ samples shows a similar type of the texture for both the phases, difference being in the intensity of the texture fibers. Martensite (α′) formation during OQ increased the microhardness, whereas coarsening of grains during FC decreased the microhardness of the samples. There was ~ 23% variation in the modulus of elasticity (E), which depended on the heating temperature and cooling rate.

Item Type:	Journal Article
Publication:	Journal of Materials Engineering and Performance
Publisher:	Springer
Additional Information:	The copyright for this article belongs to Springer.
Keywords:	Aluminum alloys; Coarsening; Cooling; Heat treatment; Iron alloys; Martensite; Microhardness; Ternary alloys; Titanium alloys; Vanadium alloys; Volume fraction, Alpha phase; Cooling rates; Electron back scatter diffraction; Electron backscatter diffraction; Furnace cooling; Heating temperatures; Microstructure-texture; Oil quenching; Pole figure; Ti-6al-4v, Textures
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	10 Feb 2023 08:38
Last Modified:	10 Feb 2023 08:38
URI:	https://eprints.iisc.ac.in/id/eprint/80152

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