Influence of the properties of Ti6Al4V powder materials on the build quality of laser powder bed fusion - manufactured components

The building quality of the LPBF (laser powder bed fusion)-fabricated component is critical to determine whether it can be applied in the serving condition. However, it is determined not only by process parameters; the powder property and its affecting factors such as average particle sizes and particle size distribution of powder materials have also significant effect on the building quality. In order to investigate the correlation between the building quality and powder properties, five kinds of powder materials with different average particle sizes and particle size distributions of Pμ20,σ10, Pμ35,σ10, Pμ50,σ10, Pμ35,σ5, and Pμ35,σ15 are prepared on the basis of the Horsfield filling method. The powder properties such as flowability and apparent density are tested, the build qualities such as dimensional accuracy and surface roughness are measured, and their correlation is analyzed. The results show that the powder material with a narrower particle size distribution benefits flowability. That with medium particle size distribution and average particle size, such as
Pμ35,σ10, possesses the highest apparent density and acceptable flowability, and the components manufactured with such powder material have the best surface roughness and dimensional accuracy. Besides, an amount of fine particles is required to optimize component density. The above systematic experiments exhibit the correlation among the particle size distribution and the average particle size, powder properties, and build quality, which is beneficial to preparing the powder materials, improving the irradiation conditions of the laser beam, controlling the LPBF process, and further the building quality of LPBF-fabricated component.