УДК 621.162 M. Betiuk, K. Burdy ski, I. Pokorska, P. Wach INFLUENCE OF ION ETCHING GENERATED BY USING , ELECTRODES IN LOW PRESSURE ARC DISCHARGE IN PLASMA ON DUPLEX COAT ADHESION The aim of this study was duplex process parameters optimalization where the main attention connects ion etching process of nitriding layer. <...> The range of our works: technological experimental contain with ion etching generated by using Cr, Ti, electrodes, optimalization of gas nitriding and PA PVD-Arc processes, SEM investigation of nitrided surface after ion etching, hardness and tribological investigation and adhesion and corrosion investigation. <...> Duplex layer obtain by gas nitriding and PAPVD-Arc processes, may be used for improve mechanical, tribological and anticorrosion properties of tools, dies and machine parts. <...> Destination of that technology is for large and middle enterprises, which produce tools and special machine elements. <...> INTRODUCTION The PAPVD method has been widely used since several years to enhance the surfaces of machine components and tooling. <...> It is, however, undergoing modifications, both in the process of coating synthesis, as well as in the processes applied prior to the actual coating deposition. <...> Among the methods applied prior to the PAPVD process, an ever more frequently used method is nitriding where research is concentrated on the formation of a layer of optimum microstructure and phase composition. <...> In the light of most recent research, the nitrided case, foreseen as a substrate for coatings produced by PAPVD, should comprise exclusively the internal nitriding, or diffusion case [1]. <...> Of significance to the adhesiveness of the PVD coating to the nitrided steel is the surface condition obtained as the result of physical treatment, e.g. polishing and ion etching by metallic ions, as well as the type of ions in the metal utilized in the etching process. <...> EXPERIMENTAL Investigations of the effect of ion etching in the process of synthesizing TiN and CrN coatings were carried out on X37CrMoV5-1 grade steel, quenched from 1020 and tempered at 550 , subsequently subjected to the gas nitriding process. <...> Table 1 lists the chemical composition of the steel used for the investigations, while table 2 shows the gas nitriding process parameters. <...> After nitriding, the steel surface was polished in order to make it more <...>