Investigation of Mechanical Behaviour and Surface Roughness Properties on Copper Electroplated FDM High Impact Polystyrene Parts

Abstract

Additive manufacturing is an advanced production technique which builds up complex-shaped parts layer by layer, as opposed to subtractive manufacturing methodologies by using the .stl file as input data. The mechanical strength and surface roughness properties of polymer-based additive manufacturing components need to be improved for its efficient use in functional end tooling applications. Many research methodologies were proposed to improve the mechanical strength and surface properties of additive manufacturing components but post-processing characterization is a kind of method, which is highly concentrated in recent years by various organizations. The various coating techniques like D.C sputtering, electroforming, electroless forming and electroplating were selected in this study, and a pilot study was conducted to choose a best technique that provides better adherence of source material over target in different build orientations of 3D-printing process. Among the various techniques in pilot study, the electroplating process was selected for this study because of its better coating properties, simple procedure, low-cost and good surface finish than other technique. In this study, the tensile and flexural test specimens were fabricated with high impact polystyrene material by using fused deposition modelling technique in five different build orientations (0°, 30°, 45°, 60° and 90°). The fabricated parts were electroplated with copper of thickness 250 μ by using sulphuric acid (H₂SO₄) and copper sulphate (CuSO₄) as electrolyte solution. The electroplated and non-electroplated parts were tested for its tensile and flexural properties as per ASTM standards at room temperature to analyze the effect of electroplating over HIPS parts. The portable surface roughness tester was used to analyze the improvement in roughness properties of electroplated parts. The results between electroplated and non-electroplated parts fabricated in five different orientations were compared and validated for its application in functional end tooling applications. The results are showing that electroplating process over 3D-printed HIPS parts significantly improved its tensile, flexural and surface roughness properties when comparing to non-electroplated parts.