Materials surface modification using quasi-stationary plasma accelerators

Quasi-stationary plasma accelerators of a new generation were studied for the capability to modify surface properties of materials widely applied in engineering (carbon steels) and in microelectronics (silicon). The action of high-energy plasma flow was shown to result in hardening the samples from carbon steels, the depth (∼0.1–0.3 mm) and microhardness (more than 10 000 MPa) of the modified surface layer being sufficient for practical purposes. Exposure of silicon wafer to medium-power compression plasma flow results in the formation of periodic sub-micron spatial structures on its surface. The main factors ensuring efficient modification of various materials under the compression plasma flow action are shown to be the rapid heating of surface due to kinetic energy thermalization of compression plasma flow during its deceleration, keeping temperature and pressure at necessary levels until the completion of physico-chemical transformations in the surface layer, and the fast crystallization of the molten layer in the presence of magnetic fields induced by the currents ‘swept-away’ from the discharge device with the compression flow.