摘要
采用金相显微镜、透射电镜、扫描电镜及拉伸性能在测试研究0.11%Ce(质量分数)添加对一种Al-Cu-Li系高强铝锂合金薄板T8态时效(5%冷轧预变形+155℃时效)组织和力学性能的影响。结果表明:0.11%Ce添加明显降低合金强度,但伸长率略有增加。微量Ce添加可细化铸态晶粒组织及固溶再结晶晶粒组织;而且微量Ce添加未改变铝锂合金中时效析出相的种类,主要强化相仍然为T1相(Al_2CuLi)及θ′相(Al_2Cu),但其数量减少。铝锂合金中添加微量Ce,凝固时可形成含Ce且富Cu的Al_8Cu_4Ce相粒子,在后续均匀化及固溶处理时均难以完全溶解,导致固溶基体中的Cu含量降低,时效时含Cu析出相T1相及θ′相含量减少,合金强度降低。
Through metalloscopy, transmission electron microscopy, scanning electron microscopy and tensile tests, the effect of 0.11% Ce （mass fraction） addition on structures and tensile properties of a high-strength Al-Cu-Li alloy with T8 aging （5% cold rolling pre-deformation and aging at 155℃） was investigated. The results show that the addition of 0.11% Ce significantly decreases the strength, but enhances the elongation a little. The cast structure and re-crystallized grains after solution treatment are refined by the Ce addition. The precipitate types does not change with the small addition of Ce, and the aging precipitates are still Tl（Al2CuLi） and θ＇（A12Cu） phases, but their amount decreases. As 0.11% Ce is added to the Al-Li alloy, Ce-contained and Cu-rich ml8Cu4Ce particles form during solidification process, which cannot be completely dissolved into the alloy matrix during homogenization and solution process. The concentration of dissolved Cu in solid solution decreases, which decreases the fraction of Tl and θ＇ precipitates and lowers the alloy strength.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2018年第1期21-30,共10页
The Chinese Journal of Nonferrous Metals
基金
国家高技术研究发展计划资助项目(2013AA032401)~~
