Investigation of an early stage of the abnormal grain growth in the friction-stir welded 6061-T6 aluminum alloy

I Vysotskiy,S Malopheyev,S Mironov

doi:10.1088/1757-899x/1014/1/012025

Abstract

In this work, quasi in-situ electron backscatter diffraction (EBSD) was applied to study an early stage of the abnormal grain growth occurring in the friction-stir welded 6061 aluminium alloy during post-weld solution heat treatment. It was found that the catastrophic grain growth completed during the heating stage of the annealing treatment, and further static storage at the solutionsizing temperature provided almost no microstructural changes.

Highlights

Friction-stir welding (FSW) is often considered as a promising technique for joining of heat-treatable aluminum alloys
Quasi in-situ electron backscatter diffraction (EBSD) was applied to study an early stage of the abnormal grain growth occurring in the friction-stir welded 6061 aluminium alloy during post-weld solution heat treatment
The microstructure was dominated by fine- nearly-equiaxed grains with a mean boundary intercept of ~5 m. Such microstructures are typically observed in friction-stirred aluminum alloys, and are usually attributed to the continuous recrystallization operating during FSW [e.g. 10-12]

Summary

Introduction

Friction-stir welding (FSW) is often considered as a promising technique for joining of heat-treatable aluminum alloys. Quasi in-situ electron backscatter diffraction (EBSD) was applied to study an early stage of the abnormal grain growth occurring in the friction-stir welded 6061 aluminium alloy during post-weld solution heat treatment. It was found that the catastrophic grain growth completed during the heating stage of the annealing treatment, and further static storage at the solutionsizing temperature provided almost no microstructural changes.

Results

Conclusion