深过冷Ni-Sn亚共晶合金的组织演化  

Microstructure Evolution of Ni-Sn Hypoeutectic Alloy in High Undercooling Solidification

作　　者：郭雄[1] 林鑫[1] 张云鹏[1] 张强[1] 黄卫东[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《铸造技术》2012年第12期1365-1368,共4页Foundry Technology

基　　金：国家自然科学基金50971102和51271213;国家重点基础研究发展计划(973)2011CB610402;高等学校学科创新引智计划08040;高等学校博士学科点专项科研基金20116102110016

摘　　要：采用熔融玻璃净化法+循环过热法,考察了Ni-28%Sn、Ni-30%Sn亚共晶合金在不同过冷度下的冷却曲线和组织演化规律。结果表明,成分偏离共晶成分较近的Ni-30%Sn合金比成分偏离共晶成分较远的Ni-28%Sn合金更易获得较大的过冷度,更易于出现再辉过程;同时,深过冷凝固情况下,两种成分的凝固组织差别较大。同Ni-30%Sn合金凝固组织相比,Ni-28%Sn合金的层片状(α-Ni+Ni3Sn)规则共晶组织容易被抑制,非规则反常共晶形成困难,初生α-Ni枝晶组织粗大,依附在其周围生长的Ni3Sn晕环组织更易大范围的形成。By using molten glass fluxing and superheating cycling, the cooling curves and microstructure evolution of Ni-28%Sn and Ni-30%Sn hypoeutectic alloy during high undercooling solidification were investigated. It is found that the Ni-30%Sn alloy, whose composition is deviated from the eutectic composition more closely, get the larger undercooling and the recalescence is easier to be generated than the Ni-30%Sn alloy, whose composition is far away from the eutectic composition. Meanwhile, there is also a large difference of solidification microstructure between Ni-28%Sn and Ni-30%Sn alloys. Compared with the Ni-30%Sn alloy, in the Ni-28%Sn alloy, the regular lamellar eutectic is easier to be suppressed during high undercooling solidification, the formation of anomalous eutectic is more difficult to form coarse primary α-Ni dendrites, and the Ni3Sn halo ring microstructure around the α-Ni dendritic arms is also easier to form in large range.

关 键 词：深过冷 Ni-Sn亚共晶合金 冷却曲线 组织演化 晕环 

分 类 号：TG146.15[一般工业技术—材料科学与工程]