Sono-capillary effect improves wetting and promotes activation of inclusions or secondary solid phases in a sonicated liquid metal environment. As a result the solidified matrix is reinforced while structural integrity and soundness in the as-cast product is achieved.

Our observations of the almost instantaneous re-filling of a micro-capillary channel with the metallic melt is highly important, as it appears to confirm the existence of the sono-capillary effect in technologically important liquids, other than water, like metallic alloys with substantially higher surface tension and density.

Results, using synchrotron radiography, showed that a pressure up to 15 MPa exerted by the liquid micro-jet upon bubble implosion in the vicinity of the capillary opening is sufficient for filling tiny capillaries such as grooves/cracks in the range of a few microns in size.