Active screen plasma nitriding - an overview

Extensive researches carried out over the past few years have shown that the novel active screen plasma nitriding (ASPN) technique can be used to treat low alloy steels, stainless steels, tool steels and other steels to achieve identical nitriding effects as the conventional DC plasma nitriding technology. Importantly, the ASPN technique provides the possibilities of treating non-electrical conducting materials such as steel with an oxidised surface and polymeric materials which are unattainable with a conventional DC plasma system. Experimental results presented in this overview further demonstrate that sputtering and deposition play important roles in nitrogen mass transfer in ASPN. In order to achieve a desirable metallurgical response, materials for the active screen and the amount of bias applied to the component have to be considered in applications of active screen plasma processing. The distance between the screen and the component surface also needs to be considered if the components to be treated are placed in a floating potential.