Effect of Gd on microstructure and refinement performance of Al-5Ti-B alloy

Al-5Ti-B and Al-5Ti-B-Gd master alloy refiners were fabricated by fluorine salt casting method. The microstructure phase constitution of the alloys investigated scanning electron microscopy (SEM), transmission (TEM) X-ray diffraction (XRD). results show that Al-Ti-B refiner consists Al3Ti TiB2 phase. After Gd is introduced into intermediate alloy, Ti2Al20Gd appears in size significantly reduced, Ti-Al-Gd found edge At same time, some independent phases appear local areas, which are determined micro-area analysis. Analysis calculation high-resolution images Ti2Al20Gd/Al structure there no other compound at junction between Al, has a great difference atomic space with α-Al, cannot be directly used as heterogeneous nucleus. But, after being decomposed aluminum melt, can promote refinement effect refiner. In Al-Ti-B-Gd many dispersed particles less than 1 µm, refining effect.