Formation mechanism of new corrosion resistance magnesium thin films by PVD method

Magnesium thin films were deposited on cold-rolled steel by physical vapor deposition sputtering technique. The crystal orientation and morphology of the deposited films were investigated by using XRD and scanning electron microscopy, respectively. The effect of crystal orientation and morphology of magnesium films on corrosion behaviors was estimated by measuring anodic polarization curves in deaerated 3% NaCl solution. With the increase of argon gas pressure, the morphology of the deposited magnesium films changed from columnar to granular structure and the diffraction peaks of the film became little sharp and broad. And all the sputtered magnesium films obviously showed good corrosion resistance compared with 99.99% magnesium target metal. Formation mechanism on the crystal orientation and morphology of magnesium films can be explained by applying the effects of adsorption and occlusion of argon gas.