Although additive manufacturing is often called 3D printing, it’s not literally “3-Dimensional” in that it’s actually a series of two-dimensional layers stacked on top of one another to form a part. This layering process can create varying strength relative to the properties of each plane. In advanced applications where consistent strength throughout the part is required, the layering process creates anisotropy, or varying properties in different directions.

The layering process produces concentrated strength in the XY dimensions and weaknesses in the Z direction and as a result, engineers are forced to design around the lowest mechanical properties in Z. All additive manufacturing processes are susceptible to this deficiency that can inhibit design freedom. Dry-blended carbon fiber-filled materials for Laser Sintering (LS) in particular, although incredibly strong and dense, can exacerbate anisotropy.

In this detailed technical article, the author explores causes of anisotropy in LS carbon fiber-filled materials, presents solutions, and highlights a new LS material with isotropic properties being developed by Stratasys Direct Manufacturing, EOS, ALM, and The Boeing Company.

Encapsulated carbon fiber composite
Encapsulated carbon fiber composite (a). A single powder particle with encapsulated carbon fiber (b). (Images provided by EOS)

>Read more by Steven Kubiak, Product Design & Development, 6/13/16

Developing a New Material for Stronger 3D Prints