预变形量对2519A-T9I6铝合金力学性能和组织的影响

来源期刊:中国有色金属学报2017年第12期

论文作者:董宇 叶凌英 孙大翔 张新明

文章页码:2434 - 2443

关键词:2519A铝合金;断续时效;力学性能;显微组织;预变形

Key words:2519A aluminum alloy; T9I6 thermo-mechanical treatment; mechanical property; microstructure; pre-deformation

摘    要:研究预变形量对经T9I6工艺处理的2519A铝合金组织和力学性能的影响。通过显微硬度测试、室温拉伸测试检测合金的室温力学性能,采用透射电镜(TEM)和高分辨透射电镜(HRTEM)分析合金的显微组织。结果表明:当预变形量为15%时,合金的屈服强度和抗拉强度取得最大值,分别为456.1 MPa和501.6 MPa,继续增大预变形量会导致强度下降;而合金的伸长率随着预变形量的增大而逐渐下降。2519A铝合金在T9I6工艺中强化方式主要为形变强化和析出强化;合金的形变强化效果随着预变形量的增大有增大的趋势,但提升幅度逐渐减小。预变形过程中引入的位错能够与合金在预时效阶段析出的GP区相互作用,从而改善位错分布。当预变形量增大时,基体内会发生回复作用导致位错密度减少,且后续时效过程中GP区析出被抑制,对强化相θ′相的形核产生不利影响,减弱析出强化的效果。

Abstract: The effects of pre-deformation on microstructure and mechanical properties of T9I6 interrupted-aged 2519A aluminum alloy were investigated by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), hardness tests and tensile tests. The results show that when the pre-deformation rate is 15%, both the yield strength and tensile strength of the alloy get their highest values, 456.1 MPa and 501.6 MPa, respectively. Further increasing the pre-deformation rate will decrease the strength. While the elongation decreases with increasing the pre-deformation rate. The mechanical properties of 2519A alunimiun in T9I6 treatment are contributed mainly by strain hardening and age hardening. The effect of strain hardening tends to increase with increasing the pre-deformation rate, but the rate of increase gradually reduces. The dislocation introduced by strain can interact with GP zones formed during pre-ageing and improve the distribution of dislocation. If the pre-deformation rate is too large, the occurring of recovery can decrease the density of dislocations. Also, the formation of GP zones in the following process will be inhibited, which can adversely affect the nucleation of θ′ precipitates and reduce the effect of age hardening.

相关论文

  • 暂无!

相关知识点

  • 暂无!

有色金属在线官网  |   会议  |   在线投稿  |   购买纸书  |   科技图书馆

中南大学出版社 技术支持 版权声明   电话:0731-88830515 88830516   传真:0731-88710482   Email:administrator@cnnmol.com

互联网出版许可证:(署)网出证(京)字第342号   京ICP备17050991号-6      京公网安备11010802042557号