快凝Al－8.5Fe－1.3V－1.7Si合金高温下的相稳定性
来源期刊：中南大学学报(自然科学版)1996年第4期
论文作者：曾欲晓 黎文献 李松瑞 肖于德
文章页码：440 - 443
关键词：铝合金; 高温稳定性; 快速凝固
Key words：aluminium alloys; high-temperature stabillity; rapid solidification
摘 要：采用透射电镜研究了快速凝固Al－8.5Fe－1.3V－1.7Si合金在600℃长时间热暴露后强化相的转化行为.结果发现,高温下稳定性极好的Al12(Fe,V)3Si相在600℃时粗化速率明显加快.在有些强化相颗粒粗化的同时,伴随部分小尺寸颗粒的溶解.随热暴露时间的延长,强化相体积分数减小,粗化的颗粒外形由球形变为多边形,半共格关系遭到破坏.热暴露200h后,在基体中有异常粗大的Al13(Fe,V)4形成,该相为底,X单斜结构,相内为孪晶结构.
Abstract: The transformation behavior of the strengthening phase in an AlFeVSi alloy after 600 ℃high-emperature exposure was investigated using transmission electron microscope. The results show that the coarsening rate is improved obviously for Al12(Fe, V)3Si dispersoids which have good stability at high tmperature up to 425 ℃. Small dispersoids are dissolved with the coarsening of some dispersoids at 600 ℃.With the increase of exposure time, the dispersoid volume fraction decreases; the shape of coarsining dispersoids change gradually from spheroid to polygon and the semicoherent relationship between silicide dispersoids and matrix is damaged. Unusual phases with base center monodinic structure and twinned faults are formed after 200 h exposure.
