Plasma Surface Metallurgy of Materials Based on Double Glow Discharge Phenomenon

Plasma Surface Metallurgy /Alloying is a kind of surface metallurgy/alloying to employ low temperature plasma produced by glow discharge to diffuse alloying elements into the surface of substrate material to form an alloy layer. It is different with ion nitriding technology, which is only applicable to the surface infiltration of non-metallic elements. “Double Glow Plasma Surface Metallurgy Technology”, also known as the “Xu-Tec Process” can utilize any chemical elements in the periodic table including solid metallic, gas non-metallic elements and their combination to realize plasma surface alloying, hence greatly expanded the field of surface alloying. Countless surface alloys with high hardness, wear resistance and corrosion resistance, such as high speed steels, nickel base alloys and burn resistant alloys have been produced on the surfaces of a variety of materials. This technology may greatly improve the surface properties of metal materials, comprehensively improve the quality of mechanical products, save a lot of precious alloy elements for human beings. Based on the plasma nitriding technology, the Xu-Tec Process has opened up a new material engineering field of “Plasma Surface Metallurgy”. This review article briefly presents the history of glow discharge and surface alloying, double glow discharge phenomenon, basic principle and current status of Double Glow Plasma Surface Metallurgy/Alloying. Industrial applications, advantages and future potential of the Xu-Tec process are also presented.