摘要
采用透射电镜研究Li含量对Al-3.0Mg-0.6Si合金时效析出行为的影响,分析不同Li含量合金在170℃人工时效过程中析出相的演化与分布。结果表明:Li元素的添加改变了Al-3.0Mg-0.6Si合金的时效析出行为。添加2.15%(质量分数,下同)Li的合金,球状的δ′-Al_(3)Li相成为晶内优先析出相,而针状的β″-Mg_(2)Si相在时效后期阶段才逐渐析出,并在时效192 h后形成了明显的球状δ′相加针状β″相的双相析出。而添加3.12%Li的合金在所观察的时效阶段内均未发现有β″相析出。另外,未发现含Li合金晶界位置有析出相存在,晶界附近是无沉淀析出带(δ′-PFZs)和δ′相。在时效100 h后发现添加2.15%Li的合金在δ′-PFZ区域有针状β″相析出。添加2.15%Li的合金δ′-PFZ的半宽尺寸和增长速率均大于2.68%,3.12%Li添加量的合金。
The effect of Li content on the ageing precipitation behavior of Al-3.0Mg-0.6Si alloy was investigated by transmission electron microscopy.The evolution and distribution of the precipitation phases in alloys with different Li contents during the artificial ageing at 170℃ were analyzed.The results show that the addition of Li changes the ageing precipitation behavior of Al-3.0Mg-0.6Si alloy.In the alloy with 2.15%(mass fraction)Li addition,the spherical δ′-Al_(3) Li phases are formed first in grain interiors,while the needle-shaped β″-Mg_(2) Si phases gradually precipitate at the later ageing stage.After ageing for 192 h,there are obviously dual phase precipitation of spherical δ′phase and needle-shaped β″phase formed.However,β″phase precipitation is not found in the alloy with 3.12% Li addition during the observed ageing stage.In addition,there are no precipitation phases at the grain boundaries of the Li-containing alloys,and the precipitate-free zones(δ′-PFZs)and δ′phase are found nearby the grain boundaries.After ageing for 100 h,the alloy with 2.15% Li addition precipitates needle-shaped β″phase in the δ′-PFZs regions.Both the half width size and growth rate of the δ′-PFZs in the alloy with 2.15% Li addition are greater than that of 2.68%,3.12%Li alloys.
作者
杨晓琨
熊柏青
李锡武
闫丽珍
李志辉
张永安
李亚楠
温凯
YANG Xiao-kun;XIONG Bai-qing;LI Xi-wu;YAN Li-zhen;LI Zhi-hui;ZHANG Yong-an;LI Ya-nan;WEN Kai(State Key Laboratory of Nonferrous Metals and Processes,GRINM Group Corporation Limited,Beijing 100088,China;GRIMAT Engineering Institute Co.,Ltd.,Beijing 101407,China;General Research Institute for Nonferrous Metals,Beijing 100088,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2021年第6期100-108,共9页
Journal of Materials Engineering
基金
国家重点研发计划项目(2016YFB0300802)。
作者简介
通讯作者:熊柏青(1963-),男,教授,博士,主要从事航空航天飞行器制造用高强高韧铝合金材料研究,联系地址:北京市怀柔区雁栖经济开发区兴科东大街11号有研工程技术研究院有限公司(101407),E-mail:xiongbaiq@163.com。
