Title: Predicting intragranular misorientation distributions in polycrystalline metals using the viscoplastic self-consistent formulation

Abstract

In a recent paper, we reported the methodology to calculate intragranular fluctuations in the instantaneous lattice rotation rates in polycrystalline materials within the mean-field viscoplastic self-consistent (VPSC) model. Here, this paper is concerned with the time integration and subsequent use of these fluctuations to predict orientation-dependent misorientation distributions developing inside each grain representing the polycrystalline aggregate. To this end, we propose and assess two approaches to update the intragranular misorientation distribution within the VPSC framework. To illustrate both approaches, we calculate intragranular misorientations in face-centered cubic polycrystals deformed in tension and plane-strain compression. These predictions are tested by comparison with corresponding experiments for polycrystalline copper and aluminum, respectively, and with full-field calculations. It is observed that at sufficiently high strains some grains develop large misorientations that may lead to grain fragmentation and/or act as driving forces for recrystallization. Finally, the proposed VPSC-based prediction of intragranular misorientations enables modeling of grain fragmentation, as well as a more accurate modeling of texture using a computationally efficient mean-field approach, as opposed to computationally more expensive full-field approaches.

Authors:

Zecevic, Miroslav ^[1]; Pantleon, Wolfgang ^[2]; Lebensohn, Ricardo A. ^[3]; McCabe, Rodney J. ^[3]; Knezevic, Marko ^[4]

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+ Show Author Affiliations

1. Univ. of New Hampshire, Durham, NH (United States). Dept. of Mechanical Engineering; Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Mechanical Engineering
3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
4. Univ. of New Hampshire, Durham, NH (United States). Dept. of Mechanical Engineering

Publication Date:

Mon Aug 28 00:00:00 EDT 2017

Research Org.:

Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Univ. of New Hampshire, Durham, NH (United States)

Sponsoring Org.:

USDOE; LANL Laboratory Directed Research and Development (LDRD) Program

OSTI Identifier:

1479989

Alternate Identifier(s):

OSTI ID: 1549918

Report Number(s):

LA-UR-18-22506
Journal ID: ISSN 1359-6454

Grant/Contract Number:  

AC52-06NA25396; 388715; 20140630ER

Resource Type:

Accepted Manuscript

Journal Name:

Acta Materialia

Additional Journal Information:

Journal Volume: 140; Journal ID: ISSN 1359-6454

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 42 ENGINEERING; micromechanics; crystal plasticity; second order moments; misorientation; texture