【摘要】 挤压铸造成形的过共晶铝硅合金活塞不同部位的含硅量不同．经测定，活塞顶部和顶侧部的含硅量偏高，显微组织中初晶硅的数量也相应较多；销孔部位和裙部的含硅量偏低．这种情况，对活塞的使用是有利的，也进一步证明挤压铸造工艺的优越性．更多还原

【Abstract】 The silicon content varies from part to part in sqeeze casting piston made of hypereutectic aluminum-silicon alloy.It was found that the content of Silicon on the top of a piston and the part around it is comparatively high.The amount of primary silicon in the microstructure is also correspondingly higher. But the silicon content near the pin hole and the skirt is relatively low. This kind of silicon distribution is advantageous to the use of the piston, which in turn shows the superiority of the squeeze casting technology更多还原