Low-temperature pressureless consolidation of AlSi10Mg powders by low-intensity ultrasound

Abstract

Low-intensity ultrasound was applied to the pressureless consolidation of AlSi10Mg powders in a broad temperature range from 600 to 860 °C. Under static conditions, the consolidation of AlSi10Mg powders can only be achieved at 860 °C, but still with the presence of some residual unconsolidated regions. The introduction of low-intensity ultrasound at this temperature eliminates the unconsolidated regions and transforms the columnar grains observed in original directional solidification into equiaxed or globular grains. Remarkably, the application of low-intensity ultrasound significantly reduces the consolidation temperature to 620 °C, without compromising the microhardness of the resulting samples when compared to static conditions. Furthermore, by lowering the temperature to 600 °C, a well-sintered porous material is obtained through the assistance of the low-intensity ultrasound.