Effect of silicon content on size distribution and morphology of Al–Si powder particles produced by solid assisted melt disintegration (SAMD) method

Abstract

Powder particles of a commercially pure aluminium as well as some Al–Si alloys containing different amounts (6, 12 and 20 wt‐%) of Si were produced via a relatively new process termed solid assisted melt disintegration (SAMD) method. In this process, melt disintegration is achieved by introducing a solid media (i.e. NaCl) into the molten metal and stirring the slurry to produce droplets which form the powder particles after solidification. The effect of melt chemical composition (silicon content) on the size characteristics and morphology of the resultant powder particles was investigated. It was concluded that the minimum average size in the powder particle size is achieved for Al–6Si alloy attributable to its relatively low fluidity. However, SEM studies revealed that the silicon content did not have any considerable effect on the morphology of the SAMD produced powders. The powders of diameter above 38 μm were mostly spherical while powders less than 38 μm were agglomerated and showed irregular shapes.