An electron back-scattered diffraction study on the microstructure evolution of severely deformed aluminum AI6061 alloy

6th International Conference on Nanomaterials by Severe Plastic Deformation

材料科学;化学

Vaseghi, M.^1 ; Taheri, A. Karimi^2 ; Kim, H.S.^3

Faculty of Mechanical and Energy Engineering, Abbaspour College of Technology, Shahid Beheshti University, Tehran 16765-1719, Iran^1

Department of Materials Science and Engineering, Sharif University of Technology, Tehran 11155-9466, Iran^2

Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea, Republic of^3

关键词: ageing;    EBSD;    Electron back-scattered diffraction;    Electron backscattering diffraction;    Equal channel angular processing;    High angle grain boundaries;    Low angle grain boundaries;    Micro-structure evolutions;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/63/1/012089/pdf
DOI  :  10.1088/1757-899X/63/1/012089

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

In this paper dynamic strain ageing behavior in an Al-Mg-Si alloy related to equal channel angular pressing (ECAP) was investigated. In order to examine the combined plastic deformation and ageing effects on microstructure evolutions and strengthening characteristics, the Al6061 alloy were subjected to φ=90° ECAP die for up to 4 passes via route Bc at high temperatures. For investigating the effects of ageing temperature and strain rate in ECAP, Vickers hardness tests were performed. The combination of the ECAP process with dynamic ageing at higher temperatures resulted in a significant increase in hardness. The microstructural evolution of the samples was studied using electron back-scattering diffraction (EBSD). The grains of Al6061 aluminum alloy were refined significantly at 100 and 150 °C with greater pass numbers and the distributions of grain size tended to be more uniform with pass number increasing. Frequency of sub-boundaries and low angle grain boundaries (LAGBs) increased at initial stage of deformation, and sub-boundaries and LAGBs evolved into highangle grain boundaries (HAGBs) with further deformation, which resulted in the high frequency of HAGBs in the alloy after ECAP 4 passes.