E.A. Kostyukevich

Compressive plasma flows interaction with steel surface: structure and mechanical properties of modified layer

The interaction of a dense compressive nitrogen plasma flow with carbon steel specimens has been investigated. The flows were generated by a magnetoplasma compressor, in which the acceleration of a plasma is accompanied by its compression due to interaction between the longitudinal constituent of electric current and the intrinsic azimuth magnetic field. As a result, a layered structure with a total depth of up to 25 μm is formed at a specimen surface. Investigations of a surface structure and its phase composition were carried out using X-ray diffraction, Mossbauer conversion electronic spectroscopy, and optical microscopy methods, along with the studies of mechanical properties.

Formation of Submicron Cylindrical Structures at Silicon Surface Exposed to a Compression Plasma Flow

Submicron-sized cylindrical structures were obtained at the surface of silicon single crystal exposed to a compression plasma flow. A periodic structure formed by channels oriented normally to the surface was observed inside the modified surface layer. The period of the structure corresponded to the spacing of the surface formations.

Melting and crystallization dynamics of single-crystal silicon exposed to compression plasma flows

The melting and crystallization of single-crystal silicon wafers exposed to compression plasma flows generated by quasi-stationary plasma accelerators are studied by numerical simulation. The results include the phase transition kinetics described on the basis of the Kolmogorov equation. The space-time characteristics of the melting and crystallization processes for variously shaped plasma pulses are discussed. Based on the experimental data and estimates, it is concluded that thermoelectric instability plays an essential role in the formation of three-dimensional periodic structures.