Vikram, RJ and Aramanda, SK and Schliephake, D and Kauffmann, A and Choudhury, A and Heilmaier, M and Suwas, S (2024) Unveiling the Intricacies of a Ductile-Phase Toughened Intermetallic: An In-Depth Exploration of a Eutectic Mo�Si�Ti Alloy and its Mechanical Behavior. In: Advanced Engineering Materials .
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Abstract
Herein, the development of directional solidification for a novel high-temperature Mo�20Si�52.8Ti (at) ternary alloy using a modified Bridgeman type apparatus is presented. The resulting alloy exhibits a microstructure consisting of a body-centered cubic solid solution (BCCss) and a hexagonal silicide (Ti,Mo)5Si3 with approximate volume fractions of 50 for each phase. The phases exhibit a crystallographic orientation relationship with (Formula presented.) and (Formula presented.). Different solidification velocities are imposed, which reveal an inverse relationship to the lamellar spacing according to a Jackson�Hunt type scaling. Mechanical characterization using Vickers indentation demonstrates that the BCCss accommodates plasticity through dislocation motion, while the silicide phase exhibits high hardness and brittleness, serving as a crack initiation site. Crack propagation is arrested and deflected at the interface to the BCCss. Fracture toughness measurements via indentation yield a fracture toughness of 3.7 MPa�m for the silicide, somewhat higher than previously reported values for Nb-, Mo-, and Cr-based silicides at room temperature. The directionally solidified specimens show an enhanced fracture toughness attributed to a greater BCCss length scale; thus, combining the ductile and hard phases results in a ductile-phase toughened intermetallic composite. The findings open up new possibilities for the design of advanced intermetallic composites with improved toughness performance. © 2024 The Authors. Advanced Engineering Materials published by Wiley-VCH GmbH.
| Item Type: | Journal Article |
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| Publication: | Advanced Engineering Materials |
| Publisher: | John Wiley and Sons Inc |
| Additional Information: | The copyright for this article belongs to authors. |
| Keywords: | Cracks; Ductile fracture; Ductility; Eutectics; Fracture mechanics; Fracture toughness; Intermetallics; Nanoindentation; Silicides; Ternary alloys; Titanium alloys, Body-centred cubic; Crystallographic orientation relationships; Cubic solid solutions; Ductile phase; Fracture toughness, nanoindentation; Highest temperature; Intermetallic composites; Mechanical behavior; Nano indentation; Ti alloys, Solidification |
| Department/Centre: | Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) |
| Date Deposited: | 30 Aug 2024 12:55 |
| Last Modified: | 30 Aug 2024 12:55 |
| URI: | http://eprints.iisc.ac.in/id/eprint/84927 |
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