Abstract:
A new mechanism is proposed that explains the formation of a thin nanostructural near-surface layer in the alloyed zone formed during the metal surface fusion treatment under the action of a pulsed plasma jet generated by the electric explosion of conductors. The proposed mechanism is based upon the development of the Kelvin–Helmholtz (KH) instability at the plasma-melt interface. A dispersion equation is obtained for the KH problem with allowance for the viscous and capillary stresses in the melt. The dependence of the KH instability increment on the surface perturbation wavelength exhibits a maximum in a nanometer range for the relative velocities of plasma with respect to the melt (within 100–1000 m/s) achieved under real treatment conditions.