戴晓元,熊超宇,张浩

• 1:长沙理工大学汽车与机械工程学院
• 2:长沙理工大学工程车辆轻量化与可靠性技术重点实验室
• 3:长沙理工大学工程车辆安全性设计与可靠性技术重点实验室

摘要(Abstract)：

采用盐浴分级淬火的实验方法,通过测试Al-9.0Zn-2.5Mg-1.5Cu-0.15Zr-0.4Sc铝合金的电导率与硬度,绘制了其时间—温度—转换率(TTT)曲线和时间—温度—性能(TTP)曲线,利用差示扫描量热法(DSC),X射线衍射(XRD),透射电镜(TEM)等观察分析了合金等温过程中的组织变化,结合Johnson-Mehl-Avrami方程研究了合金等温过程中的相变动力学。研究表明:随着保温时间的延长,淬火态合金的电导率呈上升趋势,时效态硬度呈下降趋势;Al-9.0Zn-2.5Mg-1.5Cu-0.15Zr-0.4Sc铝合金的TTT曲线和TTP曲线的鼻尖温度在330℃附近;合金的淬火温度敏感区间为270～390℃。实验铝合金过饱和固溶体在330℃等温处理时快速分解,第二相脱溶析出速率达到最高,较大的相变驱动力和较高的扩散速率是合金第二相快速析出和长大的主要原因。合金固溶后,在淬火敏感区间之外可适当降低冷却速率,这样不仅可以保持合金的力学性能,还可降低合金的内应力。

关键词(KeyWords)： Al-9.0Zn-2.5Mg-1.5Cu-0.15Zr-0.4Sc合金;TTT曲线;TTP曲线;淬火敏感性

Abstract:

Keywords:

基金项目(Foundation): 湖南省研究生科研创新项目(CX2018B549)

作者(Author): 戴晓元,熊超宇,张浩

DOI: 10.13289/j.issn.1009-6264.2019-0095

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