【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）形成，该相为底，Ｘ单斜结构，相内为孪晶结构．更多还原

【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.更多还原