Study of Surface Properties of Fused Deposition Modelling Parts

Abstract

Fused Deposition Modeling (FDM) is one of the most commonly used Additive Manufacturing (AM) methods for converting 3D designs into physical models. The printing head melts the thermoplastic material and then extrudes the melted material through the extrusion nozzle layer by layer until the final 3D object is obtained. The build material used here is acrylonitrile butadiene styrene (ABS). The layer by layer addition of the material results in an uneven surface finish of the final product. Studies have shown that the post processing techniques like coating will have a positive impact on the surface finish as well as hardness. In this study, the specimen for the coating processes were printed as per the ASTM standards (ASTM D2240, ASTM D256) needed for mechanical tests. Different post processing techniques involving sputtering, spray painting and acetone dipping were carried out with a negligible change in specimen thickness. The samples were either coated with Copper, or dipped in acetone to smoothen the surface. These coated specimens were then tested for roughness & hardness and the results showed significant improvements. A comparison has been made between the results of different post processing techniques in order to determine the most suitable process.