Study of the influence of electron beam irradiation on the microstructural and mechanical characteristics of titanium-coated Al-Si alloy

The present study aims to study the effect of change in beam energy density on microstructural features and mechanical behavior. The results show that the beam energy density value influences Ti coating layer particles. The microstructural studies indicate the presence of nanocrystalline columnar structure and eventually lead to the transformation of cellular structure with the increase of beam energy density. With the increase of beam energy density, metallurgical defects on the original surface, including micropores and elemental segregations, were eliminated, and a remelted layer consisting of the high density of cross slips and nanostructures was obtained. At lower beam energy density, Al-based solid solution was formed, but the decrease of the lattice parameter of Al was observed with the increase of beam energy density, which may be attributed to the doping of Al with Si and Cu atoms. Lower yield strength among all samples was obtained for a sample treated at 50 J/cm2, which is 40 % less than the as-fabricated alloy. The ultimate tensile strength was initially increased for the sample treated at 20 J/cm2, but ultimate tensile strength was decreased for all remaining samples on an average of about 6–8 %.