Enhancing Surface Finish of Fused Deposition Modelling Parts

Abstract

Rapid prototyping is a manufacturing process in which a computer-aided design (CAD) model is used to fabricate a physical model without the use of fixtures, tools, and human intervention. The prototype is made by deposition of material in layers. The major advantage of this manufacturing process is that it can fabricate complex part quickly with minimum loss of material. There are many rapid prototyping techniques available commercially. Fused deposition modelling (FDM) is one of the most widely acceptable methods in industry due to its simplicity of operation and ability to fabricate parts with locally controlled properties. However, the surface of the FDM parts shows a very low surface finish. In order to find out the effect of important factors that influence the surface roughness, two machining parameters such as layer thickness and orientation are considered in this paper. The specimens are fabricated with various combination of orientation and layer thickness in a FDM machine which uses Acrylonitrile Butadiene Styrene (ABS) plastics. Roughness of the top and side surface is measured with a stylus profilometer. The parameters are classified into ‘cost component’ which comprises number of layers, part building time, part and support materials and a ‘quality component’ which comprises roughness of top and side surface. The best orientation-layer thickness combination is found out statistically considering trade-off between considering the cost and quality components. In order to enhance surface finish, the above-selected specimen is subjected to chemical post treatment which shows a significant level of surface finish.