低碳球铁石墨异质形核机制的价电子理论研究  

Study of Valence Electron Theory on the Spherical Graphite Heterogeneity Formation Mechanism in Low-carbon Ductile Iron

作　　者：曾莉[1] 刘伟东[1] 屈华[1] 张伟[1] 

机构地区：[1]辽宁工业大学材料与化学工程学院,锦州121001

出　　处：《金属材料研究》2007年第2期44-49,共6页Research on Metallic Materials

基　　金：辽宁省自然科学基金项目（20031083）与辽宁省教育厅项目（05L185）联合资助

摘　　要：基于EET理论计算了低碳球铁中石墨、CaS和MnS的价电子结构，利用价电子结构信息定义并计算了石墨、CaS和MnS的体键合能F和面键合能E。结合液态金属形核理论，用F和E分析了低碳球铁过冷液体石墨异质形核的热力学条件：G液-FG〉G液-F异质，EG^（0001）〉E异质^（111）。结合现代普遍使用的大角度晶界重合点阵模型分析了低碳球铁过冷液体石墨异质形核的结构条件：石墨晶体结构与其附着的异质质点晶体结构应具有一定的点阵重合度。The Valence electron structures （VES） of Graphite （G）, CaS and MnS in low-carbon ductile iron are calculated with Yu＇s empirical electron theory of solid and molecule （EET）. On the basis of the informations of their VES, the bond-forming energy F of unit of structure and the bond-forming energy E of crystal plane are defined and calculated. Combining with the nucleation theory of the liquid metal, the thermodynamics condition of heterogeneous graphite nucleation of undercooling liquid in low-carbon ductile iron is analyzed by the values of F and E. The thermodynamics condition is. GL-FG〈GL-FH, EG^（0001）〉EH（111）. Combining with the model of coincidence lattice of large-angle grain boundary that is common used in modern times, the structural conditions of the heterogeneous graphite nucleation of undercooling liquid in low-carbon ductile iron is analyzed. The structural condition is that there is a certain lattice contact ratio between the crystal structure of graphite and the crystal structure of heterogeneous particle attached by graphite.

关 键 词：低碳球墨铸铁 石墨 形核机制 价电子结构 

分 类 号：TG146.21[一般工业技术—材料科学与工程]