(1. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China；
2. School of Materials Science and Engineering, Shenyang Ligong University, Shenyang 110159, China)
摘 要: 建立二元合金樹枝晶生長(zhǎng)的二維元胞自動(dòng)機(jī)模型，模擬丁二腈−2.5%(質(zhì)量分?jǐn)?shù))乙醇定向凝固枝晶生長(zhǎng)和一次枝晶間距選擇過程。模擬結(jié)果表明：在給定的凝固條件下，定向凝固一次枝晶間距可在一個(gè)范圍內(nèi)變化，其具體取值與凝固歷史具有相關(guān)性。在相同的溫度梯度和不同冷卻速度下，模擬給出的一次枝晶間距上、下限與實(shí)驗(yàn)結(jié)果吻合較好，詳細(xì)分析影響定向凝固一次枝晶間距上下限的因素。結(jié)果表明：在給定凝固條件和合金系條件下，液相中無對(duì)流，影響一次枝晶間距上下限的主要因素是界面能和溶質(zhì)擴(kuò)散系數(shù)。
關(guān)鍵字: 合金；定向凝固；枝晶間距；元胞自動(dòng)機(jī)；模擬
（1. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China；
2. School of Materials Science and Engineering, Shenyang Ligong University, Shenyang 110159, China）
Abstract:A two-dimensional cellular automaton model for simulation of dendritic growth during solidification of binary alloy was built. The microstructural evolution in a directionally solidified succinonitile-2.5% (mass fraction) ethanol alloy was simulated. The results show that the primary dendrite spacing may vary in a range under a given solidification condition. Its value depends on the solidification history of the sample. The calculated upper and lower limits of primary dendrite spacing at different cooling rates are in good agreement with the experimental results. The effect factors of the solidification history dependence of the primary dendritic spacing were analyzed in detail. It indicates that the interfacial energy and the solute diffusion coefficients are the main factors if there is no convection in the liquid phase.
Key words: alloy; directional solidification; primary dendrite spacing; cellular automaton; simulation
