Practical Aspects of Sputtering and Its Role in Industrial Plasma Nitriding

Sputtering is a nonthermal vaporization process in which atoms are ejected from the surface of a solid by momentum transfer from energetic particles of atomic or molecular size. Ionized gases in plasma nitriding chambers often possess enough energy to sputter atoms from workload, fixturing, and racking surfaces that are then redeposited to the benefit or detriment of the nitriding process. This article explains how and why sputtering occurs during plasma nitriding and how to recognize and control its effects. It reviews the factors that influence the intensity of sputtering and its effects, whether positive or negative, on treated parts. It also provides recommendations for improving outcomes when nitriding titanium alloys, ferrous metals, particularly stainless steels, and components with complex geometries.