Corrosion behavior of aluminum-silicon alloys obtained by Direct Metal Laser Sintering

The work studies the corrosion behavior of two aluminum alloys with different silicon content, AlSi7Mg and AlSi10Mg, produced by an additive manufacturing process based on Direct Metal Laser Sintering. The effect of subsequent thermal treatments at temperatures in the range 200 to 400 °C is considered. The resistance to selective attack was determined by immersion tests according to ISO 11846 on specimens obtained along two different orientations with respect to the main building direction. The results show the variations of the silicon particle morphology induced by heat treatments, affecting the alloy susceptibility to selective corrosion. The effect of silicon precipitates on alloy corrosion resistance and hardness is discussed.