Effect of Time-temperature Cycles on Size and Morphology of Al Powder Particles Prepared via SAMD

Solid Assisted Melt Disintegration (SAMD) is a relatively new method for producing metallic powder particles in which the kinetic energy transferred from a rotating impeller to the melt via a solid medium causes melt disintegration. These droplets are then solidified and separated from the media to obtain metallic powder particles. In the present study, sodium chloride (NaCl) was used to produce Al-6wt%Si powder particles. A specified amount of NaCl was introduced into the aluminum alloy melt and the slurry was stirred following a specified time-temperature regime to disintegrate the molten alloy into droplets.This blend was quenched in water to solidify Al powder particles and to dissolve NaCl in water. The Al powder particles were then collected, washed, dried, and subjected to laser particle size (LPS) analysis and scanning electron microscopy (SEM). The effects of different time-temperature regimes on the size and morphology of the resultant Al-6wt%Si powder particles were investigated and the optimum conditions for obtaining the finest spherical particles were established. It was concluded that the finest and most spherically shaped Al powder particles could be produced by stirring the slurry at 690 °C for 5 min followed by water quenching.