摘要
利用透射电镜技术研究了快速凝固粉末A1-3.42Li-0.82Mg-0.12Zr合金的时效析出,并观察了时效过程中δ’相的析出与拉伸性能的关系。δ’为合金的时效强化相。533℃淬火后在自然时效状态下电子衍射揭示已有δ’相析出。110℃时效后δ’相明显可见,190℃时效后颗粒长大且分布较广,此时强度较高。230℃时效后δ’已回溶,合金软化。也观察了190℃下不同时间保持对组织与性能的影响。实验表明,合金中存在两种Al_3Zr相。微小颗粒的亚稳定的面心立方点阵的有序Al_3Zr相均布于晶内,而粗大颗粒的稳定的四方点阵的Al_3Zr相沿原粉末颗粒边界和晶界析出。前者成为时效时δ’相析出的生核处,形成δ’/Al_3Zr复合析出物。
The ageing preeipitation of the Al-3.42Li-O.82Mg-O.12Zr rapid Solidificcation powder allow was studied by TEM and the relation of the δ' phese precipitation with the tensile properties were also examined. The δ' phase is the strengthening phase during ageing. The precipitation of δ'phase occurred during natural ageing after quenching from 533℃. Ageing at 190℃ led to the increase of tensile strength. The reverse solution of δ'phase took place during ageing at 230℃ and the softening of the alloy arose. There are two types of Al_3Zr phase in the alloy. The fine metastable ordered Al_3Zr phase particles uniformly distribute in the matrix and the coarse stable Al_3Zr phase particles with tetragonal lattice exist along the prior powder boundaries and the grain boundaries.
出处
《航空材料学报》
EI
CAS
CSCD
1990年第A09期77-84,共8页
Journal of Aeronautical Materials
