Graded microstructure and texture in ultrafine grained multi-layered immiscible bimetallic system

Dash, K and Yazar, KU and Chattopadhyay, K and Suwas, S (2020) Graded microstructure and texture in ultrafine grained multi-layered immiscible bimetallic system. In: Materialia, 13 .

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Abstract

In this investigation we report the formation of a graded microstructure in copper/tantalum ultrafine grained (UFG) multi-layered composite fabricated by cross accumulative roll bonding (CARB) process at high temperatures. The microstructure, micro-texture and bulk texture evolution in the copper/tantalum composite was established. A gradient microstructure develops along the thickness of the specimen during the CARB process. The fragmentation of tantalum in between copper layers and the grain refinement with evolving passes has been explained. The deformed copper layers show rotated cube texture and deformed tantalum layers show cube texture with γ-fibre. The overall texture of copper/tantalum composite weakens after the process of ARB; copper undergoing texture randomization post annealing. The crucial role of interfaces on the evolution of texture is demonstrated. The microstructural gradient in the specimen possess equiaxed, lamellar as well as large deformed grains with tantalum's grain size being in the scale of 200 nm. The correlation of microstructural gradient with orientation relationship (OR) between copper and tantalum layers was studied, confirming higher misorientation in OR at regions under high strain. Dynamic recrystallization taking place at the copper/tantalum interface has been elaborated with the aid of microtexture analysis.

Item Type:	Journal Article
Publication:	Materialia
Publisher:	Elsevier B.V.
Additional Information:	Copy right for this article belongs to Elsevier B.V.
Keywords:	Annealing; Dynamic recrystallization; Grain refinement; Grain size and shape; Roll bonding; Tantalum, Accumulative roll bonding; Bimetallic systems; Graded microstructures; Gradient microstructure; Microstructural gradients; Multi-layered composites; Orientation relationship; Ultra-fine grained ( UFG), Textures
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	13 Oct 2020 06:41
Last Modified:	13 Oct 2020 06:41
URI:	http://eprints.iisc.ac.in/id/eprint/66145

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