Morphology stability of Al3BC phase in aluminum alloys

In this work, Al3BC was synthesized as the main reaction product in an Al-8B-2C master alloy by using the liquid-solid sintering reaction method. Morphologies of Al3BC crystals were investigated by field emission scanning electron microscopy (FESEM), which indicated that the morphology as well as the size of Al3BC remain stable at 1073-1573 K and its growth mechanism was also discussed. Since {101¯1} facets have the highest growth rate, Al3BC crystal tends to form the hexagonal prism (equilibrium crystal shape), with {101¯0} and {0 0 0 1} (or {0 0 0 3}) facets being exposed. However, Al3BC crystal also appears in tetrakaidecahedron (non-equilibrium shape), caused by the melt environment. Furthermore, the effect of Al3BC on the tensile strength and elongation of A356 alloy was studied. This work enriches the morphological characteristics about Al3BC and puts forward a new strengthening phase in particle-reinforced composite area.