Characterization of inconel 718 superalloy produced by powder bed laser melting after boriding

Inconel 718 is a nickel-based superalloy whose strength is increased by precipitation hardening mechanism, suitable for working in high temperature environments such as gas turbine engine parts in the aircraft and space industry. The alloy is characterized by its ability to maintain its high strength at high temperatures, corrosion resistance, thermal fatigue strength, oxidation resistance, easy forgeability and weldability. These mechanical properties make the alloy a preferred material for aircraft engine parts applications such as compressors and turbine disks. In the Selective Laser Melting (SLE) method, the powders laid on the table are melted with laser beams layer by layer until they form the final part. This makes it possible to create three-dimensional components with high precision and complexity. With this method, it is possible to create fully functional parts from metal powders such as cobalt-chromium, stainless steel, titanium, Inconel and the like. Boriding is a thermochemical coating method applied for surface hardening and is based on the formation of a boride layer on the surface of the base material as a result of the diffusion of the element boron into the metal surface at high temperatures. The pack boriding technique is similar to the carburization process and provides a simpler and more economical option compared to other boriding methods. In this study, it is aimed to determine the effect of different heat treatment times on the coating thickness and the phases formed in the microstructure of Inconel 718 alloy produced by SLE method. In addition, the effects of coating applications on wear, corrosion resistance and microhardness properties were investigated. Scanning electron microscopy (SEM) analysis, optical microscope analysis, X-ray diffraction (XRD) analysis, microhardness measurements, corrosion and wear tests were carried out in order to investigate the phases formed in the structure and the properties of the boriding layer formed after the boriding process.