The investigation of microstructure and mechanical properties of a FeCr matrix composite coating with added Ta

Many techniques are used both to increase the surface hardness of metals and to improve fatigue strength, wear resistance and corrosion resistance. Procedures such as physical vapor deposition, chemical vapor deposition, laser beam coating and tungsten inert gas (TIG) surface coating are examples of these methods. Tungsten inert gas (TIG) surface coating method has been an important research area among these techniques. The TIG method is preferred because it is more economical compared to other advanced techniques, has low investment cost, low maintenance cost and ease of use. Tantalum (Ta) is a chemical element used in many industrial applications, characterized by its high melting point, superior corrosion resistance and high strength properties. Tantalum coatings can improve the surface properties of AISI 304 steel. However, since it is usually not possible to coat Ta directly on the steel surface, the alloy is usually formed by adding it to matrices such as Fe-Cr. In this context, Fe-Cr-Ta alloy is applied on AISI 304 steel by TIG method. Iron-chromium (Fe-Cr) containing alloys have high strength and excellent corrosion resistance properties along with low cost. In this study, the surface of AISI 304 steel was coated using the TIG method in Fe-Cr matrix by adding tantalum (Ta) powders at different ratios (0, 5, 10, 15, 20 %). When determining the manufacturing parameters, the melting temperature of the Fe-Cr matrix was taken as a basis instead of the melting temperature of the base material. Optical microscope, SEM (Scanning Electron Microscope), EDX (energy dispersion spectroscopy) and XRD (X-ray diffraction) were used for microstructure and phase analysis after the coating process. Microhardness measurement and Charpy notch impact test were performed to evaluate the mechanical properties depending on the reinforcement ratio. According to the analysis results, the presence of dendritic structures in the microstructure was determined. The results obtained in hardness and impact tests differed depending on the amount of reinforcement. Keywords: Rare element, TIG (Tungsten Inert Gas) welding method, Composite material