Investigating and comparing the surface modification of St37 steel due to the interaction with nitrogen ions using two different plasma sources

The surface modification of St37 steel irradiated with two different plasma regimes was investigated and compared. At first, using a plasma focus device, the interaction of high-energy nitrogen ions, colliding with the specimen in a pulsed manner (in nanosecond time scale) was studied. Then, the interaction of nitrogen ions with the specimens in the glow discharge plasma regime was investigated. Using SEM, EDS and XRD Analyses the morphology changes of the samples were studied. The SEM images show that small, dense and abundant bubbles (about 100 nm) were created by the pulsed plasma source on the surface of the specimens. On the other hand, the glow discharge plasma has created blisters with a size between 0.5-2 micrometers on the surface of the samples. The XRD results indicate the chemical reaction of nitrogen ions with iron in the glow discharge plasma regime. Also, the Vickers hardness test results illustrated that the hardness of the samples increased significantly.