3D printing of low melting temperature alloys by fused deposition modeling

Fused deposition modeling (FDM) is the most commonly used 3D printing technique that directly extrudes molten materials layer by layer and overcomes the constraints of fabricating complicate geometries. This technique is fast, relatively easy to perform, thus more economical compared to other 3D printing methods. However, the materials that can be extruded by FDM are limited to polymers at the present time. This study aimed to develop a fused deposition modeling for metals (FDMm) system that can deposit metallic structures directly on a platform. An extruding nozzle designed by the researchers was connected to a commercial fused deposition machine to extend the materials selection from polymers to low melting temperature metals. Continuous Sn99.3Cu0.7 lead free solder and Sn60Pb40 lead free solder were successfully extruded in a linear shape and showed that the fabrication parameters for metals are significantly different from those for polymers. Controlling the fabrication parameters also allowed the deposition of metal at a uniform geometry. Optical microscopy and scanning electron microscopy were used to analyze the FDMm-fabricated samples. Good layer to layer bonding and overall material strength can be achieved by fine-tuning of process parameters.