采用X射线衍射仪、电子探针和扫描电镜等研究了快速凝固条件下A356-K2ZrF6体系熔体反应法原位合成Al3Zr/A356复合材料的凝固组织.结果表明:单辊旋淬快速凝固条件下原位合成的Al3Zr颗粒细小,呈长方体状,尺寸为3~4 μm,比常规金属型凝固增强颗粒尺寸减小1~2 μm,同时单辊旋淬快速凝固相对于常规金属型凝固增强颗粒更易于被凝固前沿的枝晶所捕获,颗粒分布更加均匀;另外单辊旋淬快速凝固相对于常规金属型凝固复合材料基体A356合金组织中的初晶α-Al细小,共晶硅相形态大部分以颗粒状或小块状存在,且在基体中分布均匀.

The solidification microstructure of the in-situ synthesized Al3Zr/A356 composites by the direct melt reaction method in the A356-K2ZrF6 system under rapid solidification condition was investigated by X-ray diffraction,transmission electron microscope and scanning electron microscope.The results indicate that the Al3Zr particles synthesized under rapid solidification of single roller melt spinning was fine and in the shape of rectangle,the size was about 3-4 μm,which was 1-2 μm shorter than that of the particle under the conventional metal mold solidification.And compared to the conventional metal mold solidification,the reinforced particles under rapid solidification became easier to be captured by the dendritics in the rim of the solidification,and the particles distributed more uniform.Its primary crystal α-Al in the composite substrate A356 alloy become refiner,eutectic silicon existed in the forms of granulate and small bulk,which uniformly distributed in the substrate.