(1. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150001;
2. 西北工業(yè)大學(xué) 凝固技術(shù)國家重點實驗室，西安 710072)
摘 要: 對包晶合金定向生長特性進行分析，并與共晶系經(jīng)典共生生長模型(Jackson-Hunt模型)所描述的共生生長特性進行對比，提出包晶穩(wěn)態(tài)過熱共生生長模型，同時以Fe-Ni合金系為對象，對其亞包晶和過包晶成分在不同溫度梯度G和生長速度v下進行定向凝固實驗及組織分析。研究結(jié)果表明：在定向凝固條件下，包晶系兩相嚴(yán)格的共生生長只有在進入穩(wěn)態(tài)且溫度高于包晶相變溫度時才可能進行；包晶合金兩相的共生生長尤其在G/v值高的平/胞界面形態(tài)，確實發(fā)生在Tp溫度以上，與提出的模型所預(yù)測的一致。
關(guān)鍵字: 包晶合金；共生生長；Fe-Ni合金；定向凝固
of peritectic alloys
LI Shuang-ming2, LIU Lin2
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The growth characteristic of peritectic alloy during directional solidification was analyzed theoretically and compared with the growth characteristic described in the classical eutectic coupled growth model (Jackson-Hunt model), and a superheating steady state coupled growth model for peritectic alloy was presented. The microstructures of Fe-Ni peritectic system with hypo- and hyper-composition directionally solidified were investigated at different temperature gradients and growth velocities. The results show that the strict coupled growth between primary and peritectic phases only takes place at the temperature higher than peritectic phase transformation temperature in steady state. The temperature of coupled growth of the two solid phases is really above the peritectic reaction temperature. The theoretical and experimental results are confirmed each other.
Key words: peritectic alloys; coupled growth; Fe-Ni alloy; directional solidification
