( 中南大学 材料科学与工程学院,长沙 410083)
摘 要: 通过拉伸测试、显微硬度测试、透射电镜及扫描电镜分析等手段研究了预变形对2519铝合金组织与力学性能的影响。结果表明:预变形降低了合金于180 ℃时效第一阶段的硬化效果, 提高了合金峰值硬度及强度,缩短了峰值时效时间。预变形合金强度、硬度的提高是由于θ′相的数目增加和尺寸减小。细小弥散的θ′相有利于阻碍位错的运动,提高了合金的强度,同时也降低了合金的塑性。综合考虑合金的强度和塑性,2519铝合金时效前的预变形以15%为宜。
关键字: 2519铝合金;预变形;时效;力学性能;显微组织
2519 aluminum alloy
( School of Materials Science and Engineering,
Central South University,Changsha 410083,China)
Abstract: The effect of pre-deformation on the microstructures and mechanical properties of 2519 aluminum alloy were investigated by means of tensile test, microhardness test, transmission electron microscope and scanning electron microscope. The results show that the pre-deformation decreases the hardening effect of the first stage, increases the peak hardness and tensile strength and reduces the time of peak aged at 180 ℃. The peak hardness and tensile strength of the pre-deformed alloy are increased because of quantity increasing and refinement of θ′ phase. The fined and dispersed θ′ phase can strongly retard the movement of dislocations, improve the tensile strength of the alloys, at the same time, the plasticity of the alloy is decreased. The pre-deformation of 15% for 2519 aluminum alloy is better according its tensile strength and plasticity
Key words: 2519 aluminum alloy; pre-deformation; ageing; mechanical properties; microstructure