Ghazinejad Laboratory at UC San Diego

FDM/FFF Metal Additive Manufacturing

March 2023 - Present

Fused filament modeling (FDM) additive manufacturing (AM) is a popular, low-cost means to produce prototypes, low-volume production parts, and parts with complex geometry. Traditionally, FDM AM was only available to the consumer with polymer and composite filaments. However, with a few, low-cost modifications to consumer FDM printers, a specialized filament may be used to print metal parts. This filament is usually 10-30wt% PLA binder, with the remaining being a metal powder. There are 3 main steps:

1. Printing is almost identical to polymer printing, with similar temperatures and extrusion. It results in a part geometry that is still 10-30wt% binder, with dispersed metal powders. This is referred to as a green part.

2. Debinding is a one or two stage process by which the binder is removed. It is almost always done by heating the part in a furnace to vaporize the PLA, and sometimes involves a prior chemical debining step where the binder is chemically partially removed. This results in a brown part.

3. Sintering involves putting the part in a furnace to sinter all the metal particles together.

Each of the steps has their own challenges, with dozens of controllable variables. Ultimately, we are interested in the shirnkage, geometry, and physical properties of the sintered part.

This research started as my senior design project, and you can view my group's work here: https://sites.google.com/eng.ucsd.edu/mae156bteam12spring2023/home 

I am continuing this project as part of my Master's thesis, focusing on copper.

Keywords: Metal Additive Manufacturing, FDM, FFF, SEM, EDS, TGA, Optical Microscopy, Characterization

[WIP]