USING OF THE DIELECTRIC BARRIER DISCHARGE FOR DETECTION OF THE SURFACE DEFECTS OF MATERIALS

Abstract

Modern requirements to the quality of materials entail the necessity of refining methods for their control and developing various procedures for analysis of the state of the surface with the goal of having defect-free structures for high-precision instruments and devices. Gas-discharge visualization of the defects at atmospheric pressure consists in obtaining bright plasma formations in the vicinity of the surface with a defect against the background of a weak glow of the air plasma in electromagnetic fields of high strength. The potentialities of plasma technologies regarding testing the surfaces of solid materials for various kinds of defects using a self-sustained dielectric barrier discharge (DBD) at atmospheric pressure are considered. The developed rapid technique provides quick rejection of defective materials or samples prior to their technological use. A set of diagnostic tools and auxiliary equipment has been developed to visualize the mechanical defects of different origin and evaluate the quality of raw materials. A number of important issues are considered when controlling the quality of high-grade surfaces, transparent and opaque materials, including metal surfaces. The special attention is paid to the search for defects in the structural elements of industrial equipment and determination of the degree of moisture of fibrous structures, for example, woven materials.