DOC《Mg-Cu合金共晶组织形貌及CuMg2的小平面特性》

3 结论 1)Mg-Cu亚共晶合金中,领先相为α-Mg,共晶转变以前先在初生α-Mg相形成CuMg2相晕圈相,再进行共晶生长.而Mg-Cu过共晶合金中,领先相为CuMg2相,共晶组织直接在CuMg2相上形核生长.富铜区的Mg-Cu共晶合金中,领先相为Cu2Mg相,共晶组织为Cu2Mg/CuMg2,并未出现晕圈相. 2)Mg- Cu亚共晶合金中,随着铜含量的增加,共晶组织的数量逐渐增多,而初生枝晶逐渐减少,且初生枝晶的形貌没有变化. 3)Mg-Cu合金系中存在两种金属间化合物相:CuMg2相和Cu2Mg相.其中CuMg2的各向异性较强,呈现典型的小平面生长方式,而Cu2Mg以蔷薇花形的枝晶形式生长,为典型的非小平面生长方式. 参考文献 [1] Kurz W, Fisher D J. Fundamental at solidification[M]. 4th edition. Switzerland:Trans Tech Publication,1998:93. [2] Elloott R. Eutectic solidification processing-crystalline and glassy allors[M]. London:Butterworths,1983:92. [3] 李双明,马伯乐,李晓历,等. 定向凝固下共晶合金中相的竞争生长[J]. 中国科学(E),2005,35(5):479-489. [4] Pierre, Wang Haden, Guerin Raham. Tranverse thermal effects in directional solidification[J]. J Crystal Growth,2002,244(1):108-122. [5] Caram R, Milenkovic S. Microstructure of Ni-Ni3Si eutectic alloy produced by solidification solidification[J]. J Crystal Growth,1999,198/199(1):838-843. [6] 曲士昱,王荣明,韩雅芳. Nb-Si系金属间化合物的研究发展[J]. 材料导报,2002,16(4):31-34. [7] Gao Wei, Li Zheng Wei, Wu Zheng, etal. Oxidation behavior of Ni3Al and FeAl intermetallics under low oxygen partial pressures[J]. J Intermetallics,2002,10(3):263-270. [8] Meng Jie,Jia Cheng Chang,He Qing. Effect of mechanical alloying on the structure and property at Ni3Al fabricated by hot pressing[J]. Journal of Alloy and Compounds,2006,421(1/2):200-203. [9] Ren Zhongming,Li Xi,Wang Hui. The segregated structure of MnBi in Bi-Mn alloy solidification under a high magnetic field[J]. Material Letters,2004,58(27/28):3405-3409. [10] Zheng L L,Lrson D J,Zhang H. Revised form of Jackson-Hunt theory:application to solidification of MnBi/Bi eutectics[J]. J Crystal Growth,2000,209(1):110-121. [11] 陈国良. 金属间化合物结构材料研究现状与发展[J]. 材料导报,2002,14(9):1-5. [12] 杨晓华,铝涛,丁华东. 金属间化合物增韧机理[J].稀有金属材料与工程,1996,25(4):1-4. [13] 朱鹏超,李双明,郑元斌,等. 定向凝固恒速和跃迁加速下Cu-12.58%Mg过共晶合金的凝固组织演变[J].铸造,2009,58(6):543-546. [14] 刘安生. 二元合金状态图集[M]. 北京:冶金工业出版社,2004. [15] Nave M D, Dahle A K, StJohn D H. Halo formation in directional solidification[J]. Acta Materialia,2002,50:2837-2849. [16] 夏鹏举,蒋百灵,张菊梅,等. Mg-Al共晶凝固组织形貌及其影响因素[J]. 特种铸造及有色合金,2009,29(6):491-493. [17] 闵乃本. 晶体生长的物理基础[M]. 上海:上海科学技术出版社,1982. [18] Dantzig J A, M Rappaz. Solidification[M]. Lausanne:EPEL Press,2009. [19] 李珍珍,李双........