Pack aluminizing by induction heating: application to Inconel 718 produced by cold spray additive manufacturing

Abstract This study investigates the formation of aluminide coatings on Inconel 718 (IN718) superalloy produced by Cold Spray Additive Manufacturing (CSAM) using Pack Induction Aluminizing (PIA) process. The advantage of the proposed method is that the aluminizing time, which takes several hours in conventional pack aluminizing performed in furnace, can be reduced to a few tens of minutes. The microstructure, phase evolution, and tribological performance of the resulting coating were also characterized in the study. The results showed that increasing the processing time from 5 min to 10 min increased the coating thickness from approximately 10 μ m to 19 μ m, resulting in the formation of a double-layered aluminide coating. XRD and EDS analyses determined that the main components of the coating were aluminum-rich intermetallic compounds with an outer layer of Ni(Fe,Cr)Al 3 and an inner layer of Ni 2 (Fe,Cr)Al 3 , characteristic of a high-activity aluminizing process. The PIA process significantly improved the tribological properties of the IN718 substrate. Specifically, friction coefficient slightly decreased, wear resistance increased, and wear track depth decreased by approximately 80% compared to the uncoated alloy. These findings demonstrate that the PIA method is a highly effective and rapid technique for producing protective, high-performance aluminide coatings on IN718 superalloy fabricated by cold spray additive manufacturing.