Nitriding, carburizing and duplex treatment solve different surface-engineering problems and should be compared through load case, material and geometry.
Treatment routes
Plasma nitriding forms a nitrogen-modified diffusion layer; carburizing increases carbon content; duplex treatment combines diffusion modification with functional coating deposition.
Selection criteria
Important criteria include material, treatment temperature, distortion tolerance, layer depth, hardness profile, contact load and surface-function requirements.
Duplex approach
Duplex treatment is strongest where the substrate requires load support and the external interface requires coating-specific tribological or protective behavior.