☆ 4.7 Article

Microstructure, mechanical properties and deformation characteristics of Al-Mg-Si alloys processed by a continuous expansion extrusion approach

JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY (2021)

Journal

JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY

Volume 80, Issue -, Pages 150-162

Publisher

JOURNAL MATER SCI TECHNOL

DOI: 10.1016/j.jmst.2020.11.055

Keywords

Al-Mg-Si alloy; Continuous expansion extrusion forming; Microstructure; Mechanical property; Finite element analysis

Funding

National Natural ScienceFoundation of China [51774124, 51671083, 52074114]
HunanProvincial Natural Science Foundation of China [2019JJ40017]
KeyTechnologies R&D in Strategic Emerging Industries and Transformation in High-tech Achievements Program of Hunan Province [2019GK4045]
Graduate Training and Innovation Practice Baseof Hunan Province

Ask authors/readers for more resources

Protocol

Community support

Reagent

Community support

Automated Summary New
Abstract

The strength and ductility of Al-Mg-Si alloys processed with double-pass CEEF were improved synchronously. The grain size of the processed alloy was refined remarkably, and the homogeneity of microstructure was gradually improved. The processed alloys also exhibited fine (sub)grains and high-density dislocations, leading to more needle-shaped precipitates and larger precipitate aspect ratio compared to the untreated alloys.

In the present work, a double-pass continuous expansion extrusion forming (CEEF) process was proposed for an Al-Mg-Si alloy, in which the diameter of rods was gradually expanded. The microstructural evolution, mechanical properties and deformation characteristics were investigated by utilizing microstructural observations, mechanical testing and a finite element method coupled with a cellular automata model. The results showed that the strength and ductility of the double-pass CEEF processed Al-Mg-Si alloys were improved synchronously, especially in artificially aged alloys. The grain size of the processed Al-Mg-Si alloy rods was refined remarkably by continuous dynamic recrystallization (CDRX) and geometric dynamic recrystallization (GDRX), and the homogeneity of microstructure was gradually improved with increasing number of processing passes. The artificially aged alloy processed with double-pass CEEF and water quenching contained fine (sub)grains and high-density dislocations, which resulted in more needle-shaped. precipitates and a larger precipitate aspect ratio than the as-received and air-cooled CEEF alloys owing to the different precipitation kinetics. The severe cumulate strain and microshear bands were found to accelerate CDRX and GDRX for grain refinement between adjacent positions of the parabolic metal flow due to the special temperature characteristics and large shear straining during the CEEF process. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Authors

I am an author on this paper

Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7

Not enough ratings

Secondary Ratings

Novelty

Significance

Scientific rigor

Rate this paper

Microstructural Evolution and Mechanical Properties of a Continuously Cast Al-Mg-Si-Cu Alloy Processed by Repetitive Continuous Extrusion Forming

Long Zhang, Ruiqing Lu, Jie Tang, Fulin Jiang, Dingfa Fu, Hui Zhang, Jie Teng

Summary: A continuously cast Al-Mg-Si-Cu alloy was processed by repetitive continuous extrusion forming (R-Conform) to refine the grain size and improve the mechanical properties. The microstructural evolution and mechanical behavior were studied through uniaxial compression deformation, finite element simulation, microstructural observation, and mechanical test. The results showed that continuous dynamic recrystallization occurred during the R-Conform process, leading to gradually refined and more uniform grain size. Solution treatment and aging further improved the mechanical properties with a tensile strength of approximately 400 MPa and an elongation of about 17.8%.

METALS AND MATERIALS INTERNATIONAL (2023)