Grain refinement of AZ91D magnesium alloy by in-situ Al 4C 3 particles

Experiments were conducted to fabricate the Al4C3 particles by powder in-situ synthesis process under argon atmosphere and examine the grain refinement of AZ91D magnesium alloy with the addition of 0.6%Al4C3(hereafter in mass fraction,%). By means of X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS), the results show the successful fabrication of Al4C3 particles. After adding 0.6%Al4C3, the average grain size of AZ91D magnesium alloy decreased from 360 mu m to 243 mu m. Based on the differential thermal analysis (DTA) results and calculations of the planar disregistry between Al4C3 and alpha-Mg, Al4C3 particles located in the central regions of magnesium grains can act as the heterogeneous nucleus of primary alpha-Mg phase.