Effect of Ti/B on fabricating TiB2p/AZ91 composites by employing a TiB2p/Al master alloy

The TiB2 particulate reinforced magnesium matrix composites (MMCs) were fabricated by adding a TiB2–Al master alloy processed via self-propagating high-temperature synthesis (SHS) reaction of Al–Ti–B systems with the different molar ratio of Ti to B (nTi:nB = 1:2 and nTi:nB = 1:2.5, respectively) to molten magnesium and using the semisolid slurry stirring technique. When the molar ratio of Ti to B is 1:2 in TiB2–Al master alloy, the TiB2–Al master alloy and TiB2p/AZ91 composites contained a certain amount of transient TiAl3 phase; however, when the molar ratio of Ti to B is 1:2.5, the TiAl3 phase was almost completely eliminated and the distribution of TiB2 particulates generally appeared to be more homogeneous throughout the magnesium matrix.