Mechanism of Formation of the Coating/Substrate Interface during the Treatment of Conductors by an Electric Explosion Plasma

Resumo

The Ti–Zr and Ti–Nb coatings fabricated by the electric explosion of conductors are studied by scanning electron microscopy, and the behavior of the coating/substrate interface is theoretically investigated. The results obtained are used to propose a mechanism for the interface relief formation. The wavy interface relief is assumed to be caused by the Rayleigh–Taylor instability. An analysis of a dispersion equation shows that the wavelength corresponding to the maximum increment is 0.92 μm for the Ti–Zr system and 1.67 μm for the Ti–Nb system. The distance between relief ridges detected in experiments is 2.5–8.7 μm for Ti–Zr and 5–11 μm for Ti–Nb. This difference is explained by the fact that the second maximum in the wavelength dependence of the instability increment can be observed in experiments.