Experimental investigation into depositing low melting point alloy utilizing fused deposition (FDM) modelling technique

Abstract

3D printing techniques are now effectively utilized for various applications, including medical, electronics, tooling, etc. One such application is the direct printing of electronic circuitry or machine tool using low melting point alloys like solder. The most common solder material is the alloy of tin and lead. However, lead is now being replaced with other elements like copper, silver, bismuth, etc., due to its hazardous nature. The current study uses fused deposition modelling to highlight the deposition of Sn-Bi, a low melting point alloy. The customized direct-type extruder head is fitted to an existing FDM printer to achieve the required deposition. The idea behind using direct type extruder assembly instead of bourdon type is to get the necessary force for pushing the metal out of the nozzle. The process window of temperatures is identified for extruding the material and suitable print speed for depositing the same. The discontinuity is observed at a particular range of parameters and filament types. The filament combinations of 1.75 and 2.85 mm are used with subsequent modifications in the extruder assembly. The nozzle diameter is varied with two filament combinations. The results for both filament types are compared in terms of continuity and uniformity in the deposition. The microstructure of the raw material and deposited beads are also analyzed. The future scope of the current setup can be its utilization for printing electronic circuits or developing a tool for rapid tooling applications.