(华中科技大学 模具技术国家重点实验室， 武汉 430074)
摘 要: 采用玻璃熔覆法使Ni-P共晶合金实现了深过冷。 随着过冷度的增加， 其凝固组织发生了一系列的变化：晶粒逐渐细化， 凝固组织从规则棒状共晶向异常粒状共晶组织转化， 最后得到显微结构细小的胞状共晶团组织。 利用单相枝晶状共晶的熔断模型， 解释了过冷熔体形成异常粒状共晶团的形成原因。熔体在深过冷条件下形成的胞状共晶组织则可以固/液界面稳定性理论来描述。
关键字: Ni-P共晶合金; 深过冷; 异常共晶; 界面稳定性
Ni-P eutectic alloy
（State Key Laboratory of Plastic Forming Simulation and Die and Mould Technology,Huazhong University of Science and Technology,
Wuhan 430074, China）
Abstract:The high undercooling of the Ni-P eutectic alloys was achieved by glass fluxing technique. With increasing undercooling, the solidification microstructures of the alloys have changed, for example, grain refinement, transformation from regular rod eutectic structure to spherical anomalous eutectic grain structure with particulate morphology; while at higher undercooling, fine regular eutectic structure was observed. The reason of formation of anomalous eutectic group can be explained by the model of single dendritic eutectic phase growth and fusion. Fine regular cellular-like eutectic microstructure formed at high undercooling can be depicted by solid/liquid interface stability theory.
Key words: Ni-P eutectic alloy; high undercooling; anomalous eutectics; interface stability
