Surface modification of selective laser melted Ti-6Al-4V by ultrasonic impact treatment and electron beam irradiation

Changes of the surface roughness, microstructure, phase composition and microhardness of selective laser melted Ti-6Al-4V samples during electron beam irradiation and ultrasonic impact treatment were investigated by contact profilometry, optical microscopy, X-ray analysis, and hardness measurement. It was shown that electron beam irradiation and ultrasonic impact treatment of the selective laser melted Ti-6Al-4V samples smooth their surface. Significant refinement of the microstructure and TiO nanoparticles formation under ultrasonic impact treatment occur causing the increase in surface microhardness. Electron beam irradiation leads to a more significant increase in both the microhardness and thickness of the melted surface layer due to martensitic transformation.Changes of the surface roughness, microstructure, phase composition and microhardness of selective laser melted Ti-6Al-4V samples during electron beam irradiation and ultrasonic impact treatment were investigated by contact profilometry, optical microscopy, X-ray analysis, and hardness measurement. It was shown that electron beam irradiation and ultrasonic impact treatment of the selective laser melted Ti-6Al-4V samples smooth their surface. Significant refinement of the microstructure and TiO nanoparticles formation under ultrasonic impact treatment occur causing the increase in surface microhardness. Electron beam irradiation leads to a more significant increase in both the microhardness and thickness of the melted surface layer due to martensitic transformation.