Novel eutectoid Ti-5Ni alloy fabricated via direct energy deposition. (15th July 2021)

• Record Type: Journal Article
• Authors: Narayana, P.L.; Kim, Jae H.; Lee, Sangwon; Won, Jong Woo; Park, Chan Hee; Yeom, Jong-Taek; Reddy, N.S.; Hong, Jae-Keun
• Is Part Of: Scripta materialia. Number 200(2021)
• Publication Date: 2021-07-15
• Subjects: Eutectoid titanium alloy -- Direct energy deposition -- Grain refining -- Heat treatment -- Mechanical properties; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2021.113918
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Direct energy deposited (DED) Ti-5Ni (wt.%) alloys promote significant grain refinement with fine equiaxed grains (~30–50 μm); they have discontinuous grain boundary α, fine eutectoid α laths (~1 μm width), and α + Ti2 Ni phases. Post-heat treatment below beta transus for 24 h stimulates the formation of near equiaxed α, and the temperature significantly influenced the microstructural constituents, which included pre-eutectoid α + retained β + Ti2 Ni (760°C), pre-eutectoid α + α' + Ti2 Ni (800°C), and fully α' + Ti2 Ni (850°C) phases. The tensile properties of the as-fabricated and the heat-treated alloy remarkably improved compared with the other conventionally processed eutectoid Ti-Ni binary alloys. Thus, the proposed approach opens up new opportunities and possibilities for fabricating other eutectoid-forming alloy systems with improved manufacturing efficiency, which can overcome limitations in the other manufacturing processes. Graphical abstract: Image, graphical abstract