Structure and Corrosion Resistance of Multi-layer Ti/TiN Films Prepared on Uranium by Arc Ion Plating Under Different Bias Voltages

Multi-layer Ti/TiN films were prepared on U and Si by using arc ion plating in different bias voltages. The microstructure and cross section morphology were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicate that the pulse bias not only affects the diffraction peak strength, but also induces a new Ti₂N phase. The multi-layer films grow layer by layer or by island expansion. As the bias voltage is increased, the directional crystals become fine, and the films become denser. Corrosion tests in 50 μg/g Cl^－ solution indicate that the multi-layer films are corroded by layers, which make it difficult for corrosion solution to reach the substrate. In this way the corrosion resistance is enhanced.