Grain Coarsening and Texture Evolution of Pre-Stretched 2219 Aluminum Alloy Sheets during Subsequent Solution Treatment

Lihui An,Jiguang Li,Shijian Yuan

doi:10.3390/met9050530

Lihui An, Jiguang Li + Show 1 more

Open Access

https://doi.org/10.3390/met9050530

Copy DOI

Abstract

During the two-pass stretch forming process for manufacturing of thin-walled aluminum alloy sheet components, abnormal grain growth may happen if an improper pre-deformation degree was conducted before solution heat treatment, which is negative to the performance and surface quality of the final components. In order to overcome this problem, the effect of pre-stretching deformation was investigated on the change of grain structures of 2219 aluminum alloy sheets. The 2219 aluminum alloy sheets were pre-stretched with various deformation degrees, and then were heated to 540 °C for about 50 min for solution treatment. The grain structures before and after solution treatment were characterized using an optical microscope (OM) and electron back scattering diffraction (EBSD). Results show that the grains grew up gradually during the solution treatment with an increase of pre-stretching. The critical pre-stretching degree is about 3%. Once the pre-deformation exceeds 3%, the grain growth is significant, especially when it reaches 5%. Moreover, the pre-stretching has little influence on the orientation distribution. Some near a copper texture {112}<111> were generated as the pre-stretching degree was increased to 5%. All the results suggest that the pre-stretching before solution treatment cannot be larger than 3% in the two-pass stretch forming of a 2219 aluminum sheet.

Highlights

The technology of deep space exploration has become important for a country as a symbol of comprehensive strength and innovation ability [1]
As a typical light and high strength aluminum alloy, 2xxx aluminum alloys are widely used in the launch vehicle and aircraft, especially the rocket propellant tank, due to its higher mechanical properties at low and high temperature, lower density, high stress corrosion cracking resistance, and better weldability [5]
It was obvious that the grains of the two kinds of 2219 aluminum alloy sheets grew up with

Summary

Introduction

The technology of deep space exploration has become important for a country as a symbol of comprehensive strength and innovation ability [1]. Higher requirements, such as lightweight, high strength and accuracy, are put forward for the manufacturing of complex thin-walled components with the rapid development of aerospace industry [2,3,4]. For the thin-walled components with a large size, they are usually manufactured using the stretch forming process, which is widely used in the field of aerospace. During the stretch forming process, the sheet material is first clamped between the two jaws of the machine and is stretched by the jaws until it completely contacted with the die surface [7]

Methods

Results

Conclusion