快凝粉末冶金铝合金的微观结构

利用Ｘ射线衍射，透射电镜及高分辨电镜对快凝粉末冶金Ａ１－８．５Ｆｅ－１．３Ｖ－１．７Ｓｉ铝合金的微观结构进行了初步观察。结果表明，合金中仅含有一种硅化物强化相，即Ａｌ＿１３（Ｆｅ，Ｖ）＿３Ｓｉ，点阵常数为１．２５６ｎｍ。发现有些分布于晶内的硅化物相与合金基体具有确定的取向关系，即｛１１０｝Ａ１基体／｛１１０｝硅化物＜１１１＞Ａｌ基体／（１１０）硅化物但是位于晶界上的硅化物与基体没有确定的取向关系，而常常存在厚度约为５０Ａ的非晶层。

MICROSTRUCTURE OF A RAPIDLY SOLIDIFIED POWDER METALLURGY AI-Fe-V-Si ALLOY

The morphology,distribution,crystallography and microstructure of the precipitates in a dispersoid strengthened,powder metallurgy Al-8.5Fe-1.3V- 1. 7Si alloy were studied by X-ray and TEM,The results show that there is only one kind of precipitate, namely, Al_13(Fe,V)_3Si, with a l.256 nm of lat- tice parameter.There is a preferred orientation relationship for intergranular dispersoids to be recognized as follows {110}Al-matrix{110}silicide <111>Al-matrix<110>silicide Examinations by high resolution electron microscopy show that a 5nm thick amorphous layer is present along a portion of the silicide-matrix interface. Therefore, silicides located at grain boundaries have a random orientation with all surrounding grains,The preferred orientation relationship is not present when the amorphous layer seperates the silicides from the alloy matrix.