Abstract:
Metal-based additive manufacturing, or three-dimensional (3D) metal printing, is a relatively new technique having potential to enable manufacturers to print small metallic parts directly rather than adopting the traditional casting method. The application of additive manufacturing is present across various industries, aerospace industry being on of the largest research group. This technique enables one to build complex geometries by increasing the degrees of freedom of design and further removes the need of after-treatment such as cutting, sanding etc. after the manufacturing. Various techniques are currently being used which include selective laser melting, electron beam melting to print metallic parts from the powdered metal. However, these techniques provide a costly solution and that is not feasible for small industries. In this thesis a new technique will be discussed. A research study was carried out to develop metallic components by combining Fused Deposition Modelling with Sintering technique. The objective of study was to evaluate the use of this approach as an alternative to casting. Small coupons of copper filament were printed and sintered for different deposition strategy and sintering time durations according to design of experiment (DOE) technique. After sintering, microstructure of coupons was studied by metallography technique and comparison was drawn between coupons. Moreover, micro hardness test was also performed to estimate the ultimate tensile strength of 3D printed copper. The grain structure and micro hardness was found to be in comparison with the casted copper however, there was non-uniformity in the grain structure as some areas still had large voids present. In light of the result obtained, optimized parameter for producing copper parts using FDMet process were recommended. The process has potential of manufacturing fully functional metal parts and can be implemented as an alternative to casting process in all engineering fields however shrinkage needs to be catered in the initial CAD model.
