摘要
通过光学显微镜和扫描电镜考察了冷却速率及Sr加入量对亚共晶Al-Si合金中共晶Si形貌变化的影响。Boltzman方程对共晶Si变质等级关系曲线拟合结果表明:随着冷却速率提高,共晶Si完全变质所需要的临界Sr量减少,共晶Si的变质等级与Sr的加入量高度相关,相关系数R^(2)大于0.99。可以推断,在正常铸造条件下,存在变质阈值。此外,在低冷却速率和高Sr量的合金中,出现局部变质不良,其原因与Al2Si2Sr形成有关。
The effects of cooling rate and Sr addition on the morphology of eutectic Si in hypoeutectic Al-Si alloy were investigated by optical microscope(OM)and scanning electron microscope(SEM)The results of Boltzman equation fitting the relationship curve of eutectic Si modification grade showed that as the cooling rate increased,the critical amount of the Sr required for complete metamorphism of eutectic Si decreased,and the modification grade of the eutectic Si was highly correlated with the amount of the Sr addition.The correlation coefficient R^(2) was more than 0.99.It can be inferred that there is a modification threshold under normal casting conditions.In addition,in the low-cooling rate and high-Sr content,local modification occurred,and the cause is related to the formation of Al2Si2Sr.
作者
周鹏飞
孙瑜
陆从相
ZHOU Peng-fei;SUN Yu;LU Cong-xiang(Yancheng Polytechnic College,Yancheng 224005,Jiangsu,China;School of Material Science and Engineering,Yancheng Institute of Technology,Yancheng 224051,Jiangsu,China)
出处
《铸造》
CAS
北大核心
2022年第4期426-431,共6页
Foundry
基金
2019校级创新团队项目(YGYKT-04)
2019校级自然科学重点项目(ygy1904)
2019江苏高校“青蓝工程”培养项目。
关键词
共晶Si
冷却速率
变质等级
变质阈值
eutectic Si
cooling rate
modification grade
modification threshold
