(西安理工大學(xué)材料科學(xué)與工程學(xué)院，西安710048)
摘 要: 基于枝晶生長(zhǎng)的擴(kuò)散界面模型，改進(jìn)元胞自動(dòng)機(jī)法，并結(jié)合有限差分法，綜合考慮濃度場(chǎng)、溫度場(chǎng)以及熔池形狀，建立Fe-0.04%C(質(zhì)量分?jǐn)?shù))合金枝晶生長(zhǎng)和溶質(zhì)濃度分布模型。模擬單個(gè)等軸晶的生長(zhǎng)形貌及枝晶尖端生長(zhǎng)速度隨時(shí)間的變化關(guān)系、多個(gè)等軸晶的生長(zhǎng)形貌和溶質(zhì)濃度分布、柱狀晶的生長(zhǎng)形貌和耦合溫度場(chǎng)后的柱狀晶-等軸晶轉(zhuǎn)變過程，并與實(shí)驗(yàn)進(jìn)行對(duì)比。結(jié)果表明：取向角對(duì)枝晶形貌有一定的影響；枝晶尖端生長(zhǎng)速度隨時(shí)間的延長(zhǎng)最后趨于穩(wěn)定；熔池形狀影響柱狀晶生長(zhǎng)形貌；溶質(zhì)主要富集在枝晶根部及晶界處。模擬結(jié)果與實(shí)驗(yàn)結(jié)果吻合較好。
關(guān)鍵字: 元胞自動(dòng)機(jī)-有限元法；枝晶生長(zhǎng)；溶質(zhì)分布；溫度分布
（School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048, China）
Abstract:Based on the diffusive interface model of dendritic growth, a new model of dendrite growth and solute concentration distribution of Fe-0.04%C (mass fraction) alloy was developed by the improved cellular automaton method, combined with the finite difference method, considered concentration field, temperature field and the shape of molten pool. This model simulated the growth morphologies of a single equiaxial crystal, the relationships between dendrite tip growth and time, multiple equiaxial crystals growth morphologies and solute concentration distribution, the growth of columnar crystal, columnar-to-equiaxed transition after coupling temperature field, and compared with the experimental results. The results indicate that the orientation angles have certain influence on dendrite morphologies, the dendrite tip growth rate tends to be stable with the extension of time in the end, the shape of molten pool influences the growth morphologies of columnar crystals, the solute concentrate in the dendrite roots and grain boundaries. The simulation results are in accord with the experimental ones well.
Key words: cellular automaton-finite difference method; dendrite growth; solute distribution; temperature distribution
