Metal extrusion (MEX), also known as freeform filament fabrication (FFF), utilizes a thermoplastic and metal powder filament (powder mixed with binder) that is heated and drawn through a nozzle and deposited layer by layer. Like BJT components, after 3D printing, the parts require debinding and sintering to consolidate the material into a near full density geometry.
Advantages of Metal extrusion (MEX) technology
Metal extrusion is an excellent process when used as a prototyping technology because it can print very fine layers and achieve precision similar to plastic models, all while being quite cost affective. This is an extremely capable prototyping technology because of its fast build times and significantly reduced cost as compared to laser sintering. Metal filament extrusion 3D printing could very well become the go-to technology for cost-effective metal prototyping.
Disadvantages of Metal extrusion (MEX) technology
The metal extrusion technology tends to leave small voids and bubbles in the part resulting from the melted mixture leaving the nozzle as it’s applied in different directions. The high binder content needed in the MEX process can make sintering difficult, resulting is significant part shrinkage during sintering. The final sintered MEX components may have a lower density and mechanical properties as compared to binder jetted or metal injection molded components.