Papers by Keyword: Al-Ti-B

Abstract: The grain refinement in a high specific strength Al-Zn-Mg-Cu casting ingot was studied by add different amount of Al-Ti-C and Al-Ti-B master alloys during casting. The optical microscopy observation shows that the grain size of ingot is greatly reduced when adding Al-Ti-B as low as 0.01 wt%. Both the average size and the size difference among samples from various locations of ingots are smaller when the alloy casted with Al-Ti-B, which indicates that Al-Ti-B is effecient for the grain refinement in the Al-Zn-Mg-Cu casting ingot.

Abstract: Melt-SHS (Self-propagating High-temperature Synthesis) was used for the preparation of Al–5Ti–1B master alloy. The quality ratio of Ti powder/TiO₂ in initial powder mixture was varied from 0:1 to 1:0. The AES, XRD and SEM were applied to evaluate the microstructure and phase componet. The results showed that the Al-5Ti-1B master alloy could be successful produced by the reaction of Al powder, TiO₂ and H₃BO₃ in Al melt, while the reaction rate was slow. The microstructure mainly presents the TiAl₃ particles with long strip shape. A significant improvement was noted both in reaction rate and in the grain refining efficiency when Ti powder was added to the reactants and the optimized ratio of Ti powder/TiO₂ was 2:3. The TiAl₃ particles were reduced and the grain refining efficiency turned bad when Ti powder was totally used to supply Ti