Ion Nitriding Equipment

Ion nitriding equipment falls under two categories: cold-wall continuous direct current (dc) technology and hot-wall pulsed dc technology. This chapter focuses on these two categories along with other important considerations for ion (plasma) nitriding equipment and processing. The other important considerations associated with ion nitriding include the hollow cathode effect, sputter cleaning, furnace loading, pressure/voltage relationships, workpiece masking, and furnace configuration options. The chapter describes five methods of work cooling from the process temperature to an acceptable exposure temperature after plasma nitriding. These include the free-cool method, cooling under partial pressure and convective gas conditions, cooling under positive pressure, cooling using a combination of nitrogen backfilled gas in conjunction with a water-cooled heat exchanger, postoxidation treatment, and postcooling. The chapter also presents some of the advantages of the pulsed plasma process.