Synthesis of Al-5Ti-1B Refiner by Melt Reaction Method

Al-5Ti-1B refiner was successfully prepared by melt reaction method. Through the thermodynamics calculation, the initial reaction temperature was determined. The influence of reaction temperature on microstructure and absorption rate of the alloy was investigated. The phase and microstructure of the alloy were observed by X-ray diffraction, scanning electron microscope and energy dispersive spectrometer. The Al-5Ti-1B refiner was extruded at high temperature to wire with the diameter of 9.5mm, and then the refinement experiment was carried out on pure aluminium. The results indicate that the refiner consists of TiB₂, TiAl₃ and α-Al, and the microstructure prepared at 850℃ is the optimum and the absorption rate of Ti and B matches the best. The TiAl₃ and TiB₂phases distribute homogeneously in the matrix after extrusion. When adding 0.2%(mass fraction) of Al-5Ti-1B refiner, the grain size of pure aluminium reduces from 3.99mm to 0.45mm