定向凝固Tb_(0.3)Dy_(0.7)Fe_(1.95)合金的取向与组织研究  

Studies on Preferred Orientation and Microstructure of the DirectionallySolidified Tb_(0.3)Dy_(0.7)Fe_(1.95) Alloys

作　　者：丁雨田[1,2] 李晓诚[1] 胡勇[1,2] 王晓莉[1] 刘妍妍[1] 王璐[1] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,兰州730050 [2]兰州理工大学温州泵阀工程研究院,温州325105

出　　处：《材料导报》2011年第10期1-4,共4页Materials Reports

基　　金：国家自然科学基金(11004091);浙江省自然科学基金(Y4090219);甘肃省自然科学基金(0916RJZA025)

摘　　要：利用区熔定向凝固设备制备了Tb0.3Dy0.7Fe1.95合金,研究了不同定向凝固生长速度下Tb0.3Dy0.7Fe1.95合金的轴向择优取向、晶体的生长方式、结晶形貌的变化规律以及它们之间的关系。结果表明,随着定向凝固生长速度V从低速10μm/s逐步增大到380μm/s,Tb0.3Dy0.7Fe1.95合金的轴向择优取向从〈110〉方向转变为〈311〉及〈110〉、〈211〉、〈533〉多种混合轴向取向,之后又转变为原来的〈110〉方向,当V≥350μm/s后,轴向择优取向变得不明显。在整个过程中出现了2个不稳定过渡阶段,即180μm/s<V<250μm/s和270μm/s<V<350μm/s。在不同的生长速度范围内晶体的生长方式逐渐由小平面生长向非小平面生长过渡,而结晶形貌依次为平面晶、胞状晶、胞枝晶和树枝晶。The Tb0.3Dy0.7Fe1.95 alloy was prepared by zone melting directionally solidified device. The variation and the relationship of the preferred orientation, the growth mode and the crystal morphology of the Tb0.3Dy0.7Fe1.95 alloy with different growth rates were studied. Results demonstrate that with the increase of the growth rate from 10μm/s to 380μm/s gradually, the axial preferred orientation of the Tb0.3Dy0.7Fe1.95 alloy changes from 〈 110 〉 orientation to 〈311〉 and mixing orientations （110〉, 〈211〉 and 〈533〉, and later to the original 〈110〉 orientation. When the growth rate V≥350μm/s, the axial preferred orientation isnlt clear. In the whole process, two unstable transitional stages 180μm/s〈V〈250μm/s and 270μm/s〈V〈350μm/s appeare. The growth mode of alloy changes from facet to nonfacet gradually and the crystal morphology transformed from planar to cellular, cellular-dendritic and dendritic with different growth rates.

关 键 词：定向凝固 择优取向 生长方式 显微组织 

分 类 号：TG113[金属学及工艺—物理冶金]