(1. 湖南大學(xué) 汽車車身先進設(shè)計與制造國家重點實驗室，長沙 410082；
2. 湖南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410082)
摘 要: 采用CA-FE模型，對同一鑄件不同尺寸的Al-2%Cu合金凝固微觀組織進行三維模擬及預(yù)測，并引入空位形成能對固相擴散系數(shù)進行了優(yōu)化。結(jié)果表明，當(dāng)鑄件直徑分別為20、40和60 mm時，柱狀晶占總晶體比率分別為65.2%、52.1%和21.4%，逐漸減少，而等軸晶所占比率逐漸增加；當(dāng)換熱系數(shù)由500 W/(m2·K)增大到5 000 W/(m2·K)時，同一鑄件中不同直徑的鑄件凝固組織中柱狀晶組織比例顯著增大。模擬結(jié)果與實驗結(jié)果吻合較好，能夠較為準(zhǔn)確地反映等軸晶和柱狀晶的分布位置、比例和大小。
關(guān)鍵字: Al-Cu合金；3D元胞自動機；固相，擴散系數(shù)；凝固組織
solidification structure of Al-Cu alloy
（1. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,
Hunan University, Changsha 410082, China;
2. College of Materials Science and Engineering, Hunan University, Changsha 410082, China）
Abstract:A 3D cellular automaton-finite element (CA-FE) method was used to predict the solidification structure of Al-Cu alloy at different casting radii, and optimized the solution diffusion coefficient in solid phase. The results show that when the casting radius changes from 10 mm to 30 mm, the proportion of columnar grains changes from 65.2% to 21.4%. With increasing heat transfer coefficient from 500 W/(m2·K) to 5 000 W/(m2·K), the proportion of columnar grains also gradually increases. The simulated results are in accord with the experimental ones well, and can accurately reflect the distribution, proportion, size of equiaxed and columnar grains.
Key words: Al-Cu alloy; 3D cellular automation method; solid phase; solution diffusion coefficient; solidification structure
