Microstructural Comparison of an Al-8.0Zn-1.8Mg-2.0Cu Alloy with Typical T6 and T76 Tempers

Bai Qing Xiong; Kai Wen; Yong An Zhang; Zhi Hui Li; Xi Wu Li; Shu Hui Huang; Li Zhen Yan; Hong Wei Yan; Hong Wei Liu

doi:10.4028/www.scientific.net/MSF.941.753

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HomeMaterials Science ForumMaterials Science Forum Vol. 941Microstructural Comparison of an...

Microstructural Comparison of an Al-8.0Zn-1.8Mg-2.0Cu Alloy with Typical T6 and T76 Tempers

Abstract:

In order to analyze aging behavior of an Al-8.0Zn-1.8Mg-2.0Cu alloy, the microstructure of the alloy subjected to T6 and T76 states are investigated by transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). Based on the precipitate observations, precipitate size distributions and average precipitate size are extracted from bright-field TEM images projected along 〈110〉_Al orientation with the aid of an imaging analysis. The results indicate that the main precipitates are GPI zone, GPII zone and η' phase in the T6 alloy while η' phase and η phase in the T76 alloy. The bright-field TEM observations reveal that the matrix precipitates for the T6 alloy have small size and dispersive distribution while that for the T76 alloy has big size and sparse distribution. Both have discontinuously distributed grain boundary precipitates. Quantitative structural information including precipitate size distribution and average precipitate size has been calculated by an image analysis based on the bright-field TEM images projected along 〈110〉_Al orientation. The results show that the T6 alloy has a narrower precipitate size range than the T76 alloy and thus the T6 alloy possesses a smaller average precipitate size than the T76 alloy.

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Periodical:

Materials Science Forum (Volume 941)

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753-758

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.941.753

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December 2018

Authors:

Bai Qing Xiong*, Kai Wen, Yong An Zhang, Zhi Hui Li, Xi Wu Li, Shu Hui Huang, Li Zhen Yan, Hong Wei Yan, Hong Wei Liu

Keywords:

Aging Treatment, Al-Zn-Mg-Cu Alloy, Microstructure, Precipitates

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