Abnormal grain growth in fine-grained aluminum produced by friction-stir welding

S Mironov,R Kaibyshev

doi:10.1088/1757-899x/672/1/012043

S Mironov, R Kaibyshev

Open Access

https://doi.org/10.1088/1757-899x/672/1/012043

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Abstract

In this work, fundamental aspects of abnormal grain growth, which typically occurs during annealing of friction-stir welded (FSW) aluminium, were studied. To this end, crystallographic orientations of abnormally-coarse grains were systematically examined. Statistical analysis showed that those were not random. Specifically, it was found that the abnormal grain growth resulted in ~30°<111> rotation of FSW-induced B/-B {112}<110> texture. Accordingly, the abnormal character of the grain growth was interpreted in terms of increased mobility of 30°<111> boundaries.

Highlights

Friction stir welding or processing (FSW/P) is sometimes considered as a relatively new technique for grain refinement of structural alloys [1, 2]
The extensive research has shown that the grain-growth behavior of the friction-stir welded (FSWed) materials could be often described in terms of Humphreys’ cellular model, i.e. arises from an imbalance between the grain-growth pressure and the pinning force exerted by second-phase particles or low-angle boundaries [7, 8]
A sample-scale electron backscatter diffraction (EBSD) map taken from the cross-section of the friction-stir welded material is shown in figure 1

Summary

Introduction

Friction stir welding or processing (FSW/P) is sometimes considered as a relatively new technique for grain refinement of structural alloys [1, 2]. Fundamental aspects of abnormal grain growth, which typically occurs during annealing of friction-stir welded (FSW) aluminium, were studied. It was found that the abnormal grain growth resulted in ~30o rotation of FSW-induced B/-B {112} texture. The abnormal character of the grain growth was interpreted in terms of increased mobility of 30o boundaries.

Results

Conclusion