Combined Electromagnetic and Mechanical Ultrasound for Particle Dispersion in Liquid Metals

Abstract

It is known that acoustic cavitation is one of the mechanisms resulting in the dispersion of small particles in liquid metallic alloys. Previous research has shown that the contactless electromagnetic method can be used to induce such cavitation and disperse particles in metals, where the application of a high-frequency alternating magnetic field plus a static magnetic field results in pressure oscillations that can become strong enough to disperse particles. Promising results have been obtained on the laboratory scale for some metal/particle pairs such as tin/silicon carbide (Sn/SiC) and chrome steel/titanium nitride (FeCr/TiN). We present herein the idea of combining such electromagnetically induced ultrasound with the application of mechanical ultrasound to a liquid melt to achieve enhanced particle mixing and dispersion. This combined method allows the achievement of a strong oscillating pressure with simultaneous significant stirring of the melt. This approach has the potential to stir and disperse particles in a single-stage process.