Parameter optimization for electron beam surface melting of Inconel 718

Electron beam surface melting is a versatile technique to ameliorate the mechanical and microstructural characteristics of superalloys. In the present study, Inconel 718 super alloy is subjected to electron beam surface melting using an indigenously developed electron beam welding unit (80 kV and 12 kW) by varying process parameters. Electron beam surface melting leads to refinement of microstructure with the presence of Ni primary dendrites and fine precipitates of Ni Al in the interdendritic spacings, which results in improvement in hardness. Withal, process parameters are optimized using ANOVA. Moreover, a detailed structure-property relationship with various process parameters is established to comprehend the mechanism of property enhancement. (author)