Ball milling as a possible means to produce zinc based coatings

Abstract

Abstract Mechanical alloying of both steel strip and elemental Zn powder (with or without Fe powder) was performed in order to directly produce zinc based coatings on the surface of steel strip. Microstructures of coatings and milled powders were investigated using X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Metastable phases, in particular Zn supersaturated with Fe were synthesized during ball milling. Iron supersaturation in FeZn alloy is almost twice as high (4.5 at.% Fe in Zn) on the milled steel strip as in the ball milled powder (2.8 at.%). The latter values remain lower than the maximum Fe solubility in Zn allowed by thermodynamics. Subsequent annealing at 300 °C forms a Γ1 monophased coating which is not usually synthesized during batch galvanizing.