A simple chemical method to remove the support structure of 3D printed Ti6Al4V alloy

Purpose The purpose of this study is to develop a simple chemical method to remove support structure from hard-to-reach areas such as internal channels and cylindrical geometries of 3D printed Ti6Al4V alloy. Design/methodology/approach As compared to already published work, the ratios of hydrofluoric acid, nitric acid and deionized water have been used to remove the support structure without significantly affecting the part dimension. Replicas of internal channels in the form of titanium cylinders with 2 mm, 1.5 mm, 1.0 mm and 1.1 mm wall thickness with internal block supports were 3D printed by selective laser melting technology. Findings Among all tested ratios of HF: HNO3: H2O, 1:4:4 ratio (7.5 ml: 30 ml: 30 ml) was found to be the best optimized to attack only the weak support structure with minimal effect on the channel dimension. In all three selected samples, there is a constant reduction in cylinder thickness (approximately 0.1 mm) after support removal, which shows that for a constant support mass-to-volume of the chemical solution an initial margin to the channel size can be predicted to compensate for the loss of material. Originality/value The proposed method was also successfully implemented on a curved cylinder to demonstrate its usefulness for complex internal channels also.