Grain refinement performance of aluminum cast by addition of spherical Al3Ti particles fabricated by gas atomization method

Abstract

In this study, grain refinement performance of aluminum cast by grain refiners containing spherical-shaped Al3Ti particles is studied. Spherical Al3Ti particles with D022 structure were prepared by gas atomization method. The sieved particles in the range of 75-150 μm and 150-212 μm were sintered with pure aluminum particles by spark plasma sintering (SPS) to obtain Al-10 vol% Al3Ti grain refiner with spherical Al3Ti particles. It is found that the spherical Al3Ti particles can become favorable heterogeneous nucleation sites for solidification of aluminum. However, grain refining performance has a strong fading trend. When the refiner was heat-treated at elevated temperature, the spherical Al3Ti particles were divided into smaller parts. This is because the spherical Al3Ti particles prepared by gas atomization method are polycrystal.