Build Processes for Functionally-Graded Materials via Direct-Write Additive Manufacturing

A method to design and fabricate functionally-graded materials (FGMs) was developed and tested for direct-write additive manufacturing (AM). Manufacturing FGMs has historically come with its own set of challenges. Naturally, AM provides a possible solution to printing structures with any type of FGM provided the appropriate routines are in place. Therefore, a set of processes for printing FGMs using a direct-write AM system was developed and successfully tested on two different direct-write AM platforms. Defining a gradient through a volume was done by assigning a mix ratio through the volume of the part using a set of parametric equations. The gradient information was calculated and assigned to tool paths generated by slicing software at the g-code level. The g-code was tested on a modified Lulzbot Taz 6 fitted with a direct-write extrusion system and on a 3D Flexible multi-material mixing platform. Using the present process, both platforms successfully manufactured several printed tokens with different gradient profiles. Proper configuration of parameters unique to 3D printing FGMs that enabled successful prints are discussed.