Study of plasma immersion ion implantation inside a conducting tube using an E × B field configuration

•PIII in E × B fields with an auxiliary electrode (AE) is more stable than without AE.•High ion dose in the tube inner wall by PIII has improved its surface properties.•Corrosion resistance inside the tube was improved after PIII in E × B fields.•Plasma formation inside the tube is facilitated at lower voltage and higher pressures.

Study of plasma immersion ion implantation (PIII) inside a cylindrical conductive tube which was biased in the presence of E × B fields has been carried out. This was initiated with the electrical characterization of the system with and without the incorporation of an auxiliary electrode (AE) inside the tube. It was shown that in the presence of an AE, the breakdown of the discharge during PIII is facilitated. In the presence of the AE and the magnetic field, higher discharge currents were measured even under moderate PIII operation parameters. In order to determine the effect of implantation inside the tube, stainless steel (SS) samples were implanted with nitrogen ions with and without the presence of AE. Samples treated under these two configurations demonstrate a remarkable difference in terms of morphological, structural, tribological and mechanical properties. Higher intensity peaks of expanded austenite were detected by X-ray diffraction for samples treated in discharges with the presence of the AE. This is a consequence of higher concentration of nitrogen implanted into SS, leading to an increase of the hardness and the achievement of better corrosion resistance.