Aging precipitation characteristics and tensile properties of Al-Zn-Mg-Cu alloys with different additional Zn contents

• 作者: Kai Wen Bai-Qing Xiong Yong-An Zhang Xi-Wu Li Zhi-Hui Li Li-Zhen Yan Hong-Wei Yan Hong-Wei Liu
• 来源期刊: 稀有金属（英文版）
• 年，卷（期）: 2021,（8）
• 所属期刊栏目: ORIGINAL ARTICLES
• 页码范围: 2160-2166
• 页数: 7页
• 语种: 英文

摘要

The increase in zinc content in Al-Zn-Mg-Cu alloys provides an effective method to enhance the strength.Transmission electron microscopy (TEM) and tensile test were employed to analyze the microstructure and tensile properties,respectively,of Al-9.3Zn-2.0Mg-1.8Cu alloy (9.3Zn alloy) and Al-9.8Zn-2.0Mg-1.8Cu alloy (9.8Zn alloy) with single-and double-stage aging states.The results showed that the two alloys possessed a closed strength under single-stage peak-aging treatment.As for double-stage aging treatment,9.8Zn alloy had a higher strength values than 9.3Zn alloy under the same aging regimes.With the second step aging time prolonging,the strength gap was extended.The main precipitates for the two alloys with single-stage peak-aging state were GP zones and η'phase,while there were a majority of η'phases and η phases for the two alloys under typical double-stage over-aging state.Under double-stage over-aging state,the proportion of precipitate with large size for 9.3Zn alloy was larger than that for 9.8Zn alloy.Besides,a more obvious trend was revealed for the double-stage over-aging state.The gap of strength between the two alloys was explained by the difference of precipitation characteristics via interaction mechanism between precipitates and dislocations.