Grain Structure Evolution and Mechanical Properties of Multi-Channel Spiral Twist Extruded AA5083

Dina M Fouad,Ibrahim Albaijan,Waleed H El-Garaihy,Mohamed M El-Sayed Seleman,Mohamed M Z Ahmed,Hanadi G Salem

doi:10.3390/met11081276

Abstract

This study presents a comprehensive evaluation of the effects of multi-channel spiral twist extrusion (MCSTE) processing on the mechanical properties and structural evolution of AA5083. The structural evolution and texture developed were mapped by electron backscatter diffraction (EBSD) for three successive passes and compared with an as-annealed plate. An evaluation of the hardness and tensile properties was presented and correlated with the EBSD findings. The displayed EBSD results revealed that grain refinement was strongly associated with the presence of a high density of low-angle grain boundaries (LAGBs) after one pass, which developed into fine grains of less than 20 μm and high-angle grain boundaries (HAGBs) after three MCSTE passes. The three pass processing led to a 65% reduction in grain size. This reduction in grain size was coupled with an enhancement in the hardness and tensile properties. Additionally, the crystallographic texture study represented a slightly random texture due to the presence of intermetallic particles in AA5083. This study demonstrates the efficacy of MCSTE as a grain refinement tool.

Highlights

Over the past two decades, extensive research has been conducted and advancements have been made in the fabrication of bulk ultrafine grained (UFG) structures with optimized properties [1,2]
electron backscatter diffraction (EBSD) data were recorded at the edge and the center of the extrudates to examine the microstructure homogeneity across the mid-section perpendicular to the extrusion direction (ED)
EBSD evaluation was conducted to analyze the grain structure evolution associated with processing AA5083 via multi-channel spiral twist extrusion (MCSTE)

Summary

Introduction

Over the past two decades, extensive research has been conducted and advancements have been made in the fabrication of bulk ultrafine grained (UFG) structures with optimized properties [1,2]. Owing to their superior properties and unique attributes, grain refinement processes have gained the attention of researchers and scientists worldwide. Strain hardening via SPD processes provides a highly effective and inevitable approach to enhance the strength of non-heat-treatable aluminum alloys, with several articles reporting promising enhancement in 5xxx series Al alloys such as AA5083 [1,17,18,19,20]. It is worth to mentioning here that, 5xxx series aluminum alloys constitute the highest strength Al alloys in the non-heat-treatable category coupled with a good weldability and corrosion resistance which supports its use in the automotive and aircraft industries [19]

Methods

Results

Conclusion