(華中科技大學(xué) 模具技術(shù)國家重點(diǎn)實(shí)驗(yàn)室， 武漢 430074)
摘 要: 采用玻璃熔覆法使Ni-P共晶合金實(shí)現(xiàn)了深過冷。 隨著過冷度的增加， 其凝固組織發(fā)生了一系列的變化：晶粒逐漸細(xì)化， 凝固組織從規(guī)則棒狀共晶向異常粒狀共晶組織轉(zhuǎn)化， 最后得到顯微結(jié)構(gòu)細(xì)小的胞狀共晶團(tuán)組織。 利用單相枝晶狀共晶的熔斷模型， 解釋了過冷熔體形成異常粒狀共晶團(tuán)的形成原因。熔體在深過冷條件下形成的胞狀共晶組織則可以固/液界面穩(wěn)定性理論來描述。
關(guān)鍵字: Ni-P共晶合金; 深過冷; 異常共晶; 界面穩(wěn)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
