中文摘要：

采用X射线衍射、扫描电镜、高分辨透射电镜等分析手段研究了在蓝宝石(0001)基面上异质形核的Al合金的晶体取向和界面结构特征。结果表明，在纯Al和Al.1%Sb(质量分数)形核体系中，靠近形核界面处的形核相择优取向分别是Al的(200)和(220)晶面，并获得了两种形核体系的位相关系。相比Al/Al2O3形核体系，Al.1%Sb/Al2O3形核体系中由于合金元素Sb的添加，降低了形核相择优生长方向的晶面间距，同时将形核相与形核基底之间的晶格错配度从Al/Al2O3形核体系的16.4%降低到7.0%，因此，Al.1%Sb/Al2O3形核体系具有更好的形核效率和更加细化的晶粒。

英文摘要：

Lattice structure information of heterogeneous nucleation at nucleation interface was present.The crystal orientation,and interfacial structure characteristic of liquid Al alloys nucleated on the basal surface(0001)Al2O3single crystal substrate were identified by X-ray diffraction(XRD),scanning electron microscopy(SEM)and high resolution transmission electron microscopy(HRTEM)analysis.The preferred crystal orientations of pure Al and Al-1%Sb(mass fraction)alloy adjacent to the nucleation interface were examined as(200)and(220)planes of Al,respectively,and two corresponding orientation relationships were obtained.An improved nucleation efficiency and refined grains were attributed to both the reduced interplanar spacing of preferred orientation and the decrease of lattice misfit from16.4%to7.0%in Al-1%Sb/Al2O3nucleation group.