【作者】 李琨； 苏彦庆； 骆良顺； 李新中； 郭景杰； 傅恒志；

【Author】 LI Kun,SU Yan-qing,LUO Liang-shun,LI Xin-zhong,GUO Jing-jie,FU Heng-zhi (School of Materials Science and Engineering,Harbin Institute of Technology, Harbin 150001,Heilongjiang,China)

【机构】 哈尔滨工业大学材料科学与工程学院；

【摘要】 采用定向凝固技术制备了Ti-45Al-5Nb合金定向凝固试样,研究了不同定向凝固参数下的凝固组织。结果表明,该合金在定向凝固过程中随着生长速度的增大,固-液界面发生粗胞枝晶→β枝晶→α枝晶的转变过程;定向凝固组织的片层取向同时受到初生相与定向凝固启动界面的影响,且启动界面的影响更为显著;Nb元素在试样内部分布不均匀,存在交替的条带状偏析现象,并且在原始枝晶间区域Nb元素分布较少。更多还原

【Abstract】 In this paper,a series of directional solidification experiments were carried out with Ti-45Al- 5Nb alloy and the directional solidified microstructures with different G/V were investigated.It was found that the morphology of S-L interface transferred from cellular to dendrite with the increase of growth velocity;the lamellar orientation was effected by both the primary phase and the starting interface of solidification which is the major fact;the distribution of Nb was inhomogeneous,which induced a banding pattern in the solidified microstructure.更多还原