EFFECTS OF POSITIONING CONDITIONS ON MATERIAL PROPERTIES IN POWDER BED FUSION ADDITIVE MANUFACTURING

Abstract

Among additive manufacturing technologies, Powder Bed Fusion (PBF) is considered the most common process. Although the PBF has many advantages, some issues must be clarified, such as positioning. In this study, the effect of positioning on the microstructures in the PBF method was investigated. Ti6Al4V samples were manufacutred in different positions on the building platform and investigated by means of temperature, porosity, microstructure and hardness. In this study, martensitic needles were detected on the microstructure samples. Some twins were noticed on primary martensitic lines and the agglomeration of β precipitates was observed in vanadium-rich areas. The positioning of samples were revealed to have an effect on temperature gradients and the average martensitic line dimensions. Besides, different hardness values were attained depending on sample positioning conditions. As a major result, cooling rates were found related to the positions of samples and the location of points on the samples.