Contactless generation of cavitation in high temperature liquid metals and its impact on particle dispersion in solidified iron and steel samples

A recently developed method for the contactless magnetic generation of cavitation is demonstrated for high-melting-point metals. The approach is based on the floating-zone technique, which is truly contactless and crucible-free as it uses electromagnetic forces. Using this method, ultra-high-temperature ceramic particles, such as TiN, TiB₂ and TiC, are admixed in liquid iron and 316L steel. The dispersion and particle refinement caused by cavitation treatment during melting and solidification are investigated. Magnetic fields up to 8 T that correspond to pressure oscillation amplitude of 0.83 MPa are used. The signal emitted by the collapsing bubbles is captured and visualized for iron melts. Samples with a higher number of cavitation nuclei exhibit a more stable cavitation response. Improved reinforcement refinement is demonstrated for increasing cavitation intensity – the size of precipitates is evidently reduced due to the cavitation treatment.