Modeling of dimensions and investigations on geometrical deviations of metallic components manufactured by mu-plasma transferred arc additive manufacturing process

摘要

This paper presents development and experimental validations of a theoretical model to predict width and total height of multi-layer single-track deposition by mu-plasma transferred arc additive manufacturing (mu-PTAAM) process and using it to investigate dimensional tolerances, and dimensional and geometrical deviations of three different components (i.e., hollow cylinder, hollow rectangular block, straight wall) of Ti-6Al-4V alloy manufactured by the mu-PTAAM process. Experimental results found that the developed model has prediction errors for width and total height of multi-layer single-track deposition in a range from - 12 to 10.21% and from - 2.3 to 2.1% respectively. Smaller values of prediction errors validate the developed model. It more accurately predicts total height of multi-layer single-track deposition. Results on dimensional and geometrical deviations of the manufactured metallic components found that 90% of the scanned data points for all three manufactured components lie in tolerance limits of +/- 1 mm, and 100% of scanned data points lie in tolerance limits of +/- 1.5 mm. Dimensional deviation is found to be - 2.45 mm in length of the straight wall at the top due to deceleration of micro-plasma torch at the ends of a straight wall. Cylindricity and concentricity of the hollow cylinder are found to be 1.21 mm and 0.53 mm respectively. Parallelism and perpendicularity of the hollow rectangular block are in the range from 0.42 to 1.12 mm and 0.62 to 1.63 mm respectively. Flatness of the straight wall is found to be 0.96 mm for the front face, and 1.22 mm for the back face. It can be concluded from this study that the mu-PTAAM process is suitable for free-form manufacturing of metallic components.