Affiliation:
1. School of Metallurgical Engineering, Xi'an University of Architecture and Technology, Xi’an 710055, China
Abstract
In additive manufacturing (AM), the characteristics of raw powder materials has great influence on both the printing process and the final properties of as-printed components. Compared with ball milling of powder materials, the dispersion method has great advantages in preventing the agglomeration of nanoparticles. In the present study, the composite powders of micro-sized Ti6Al4V with nano-Y2O3 particles were prepared by dispersion method, the influence of nano particle content on surface morphology, flowability, apparent and tap density was investigated. In addition, the relative density and mechanical properties of as-printed samples were studied. The results showed that nano-Y2O3 particles were coated on the surface of Ti6Al4V powders without changing the spherical shape through dispersion treatment. The increase of nano particle content resulted in the increase of surface roughness, while the flowability and tap density of composite powders gradually decreased. Meanwhile, the relative densities of as-printed samples decreased, small clusters of nano-Y2O3 were observed due to the poor wettability between Ti6Al4V and Y2O3 nanoparticles. The agglomeration is caused by the extremely high temperature environment near the pore area. The enhancement of microhardness was attributed to the second-phase strengthening and grain refinement effect.