Spray atomization and deposition of tantalum alloys

Abstract

A Ta Fe alloy was atomized and spray-deposited. The spray deposition process was investigated experimentally and numerically. An induction skull melting (ISM) spray forming process was used. The spray formed materials and oversprayed powders were characterized using optical microscopy, X-ray diffraction and scanning electron microscopy. A theoretical and numerical analysis was undertaken in order to gain some insight concerning the spray deposition of tantalum and complement the experimental data where measurements were impractical. These simulations are based on a previously developed multi-directional solidification model combined with a Navier-Stokes solver for flows with interfaces. Various droplet size and impact velocities consistent with the experiments were considered. The results show that liquid-jet overflow occurs only for droplets with a diameter larger than the mean size. Comparisons of the measured and calculated final splat sizes show that the numerical model gives a good estimate of the final droplet spreading behavior.