7050合金RRA沉淀析出的TEM研究

谷亦杰; 李永霞; 张永刚; 黄正; 陈昌麒

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航空材料学报 ›› 2000, Vol. 20 ›› Issue (4) : 1-7.

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论文

7050合金RRA沉淀析出的TEM研究

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TEM observation of precipitates in a 7050 alloy after RRA treatment

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摘要

采用透射电镜(TEM)和维氏硬度计研究了回归再时效(RRA)处理对7050合金的的影响。研究发现,7050合金受回归温度和时间影响。当回归温度为453K和473K时,回归曲线由三部分组成,回归再时效曲线由两部分组成。与在回归曲线上存在的峰值硬度相比,回归再时效峰值硬度要高。TEM观察表明,硬度谷值的产生与GP区的回溶有关,而峰值的产生与η′和η相的沉淀析出有关。回归再时效峰值高于回归峰值,这与回归再时效过程中η和η′相沉淀析出数目增加有关。当回归温度为493K,回归和回归再时效曲线单调下降,分析认为由于回归温度高,回归曲线上不能区分GP区的回溶、η和η′相形核、η和η′相长大及粗化这三个阶段。

Abstract

7050 alloy precipitation aging behavior has been studied by transmission electron microscopy and Vickers hardness tester after retrogression and reaging(RRA) treatment. The RRA behavior was affected by the retrogression temperature. When the retrogression temperature was at 453K and 473K, the retrogression curve can be dealt with in three stages and the RRA treatment can be simply considered as a two step aging process. The result of TEM showed that the dissolve of GP zone caused the decrease of hardness and the precipitation of η and η′ caused the increase of hardness. When the regression temperature was 493K, the hardness decreased, and no hardness valley and peak was not observed on the retrogression curve and RRA curve. Analysis indicated that the three stages of dissolve of GP zone, precipitation of η and η′ and growth of η and η′ can not be distinguished at the retrogression curve because of higher retrogression temperature.

导出引用

谷亦杰, 李永霞, 张永刚, 黄正, 陈昌麒. 7050合金RRA沉淀析出的TEM研究[J]. 航空材料学报, 2000, 20(4): 1-7

GU Yi-jie, LI Yong-Xia, ZHANG Yong-gang, HUANG Zheng, CHEN Chang-qi. TEM observation of precipitates in a 7050 alloy after RRA treatment[J]. Journal of Aeronautical Materials, 2000, 20(4): 1-7

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