In order to improve the micro-structure and the properties, the components of the nodular cast iron ball should be controlled in the point of eutectic or hyper-eutectic near the point of eutectic.
为改善球铁磨球的显微组织及性能，球铁成分应控制在共晶或稍过共晶处。
2
The crown diameter of eutectic al Si alloy piston has increased suddenly in twice, but the hypereutectic al Si alloy piston only once.
共晶铝硅合金活塞顶部直径有两次突然长大，而过共晶铝合金活塞仅有一次。
3
The dimension stability of hypereutectic Al Si alloy piston is higher than that of eutectic Al Si alloy piston.