Are 3D Printing Materials a Weakness?

For as long as I can remember, users, and potential users, have been clamoring for more and better materials for their 3D printers. It is reasonable to state the to do more with 3D printing, industry wants more in terms of material properties.

If we stop here, the answer to this blog post’s title is an unequivocal “Yes.” Materials are a weakness. But as I pointed out in an April blog post, “The diversity of 3D printing processes, with more likely to arise, will yield even more materials and perhaps even new, never-before-seen material classes.”

In the past 30 days, there have been three news items that prove that point. Objet announced 39 new Digital Materials, bringing its total up to 90 that are blended as a part is printed. What’s more, a single part can have up to 14 materials. Rochester Institute of Technology announced its selection of Optomec’s Aerosol Jet for its unique ability to dynamically mix materials during the deposition process to produce functionally graded structures. The third item came from the University of Exeter where research has resulted in an aluminum composite that is the result of a reaction within the build chamber of a selective laser melting (SLM) machine.

In each of these three cases, 3D printing is achieving material compositions and combinations that are not possible with conventional processes. That is a major advantage that is shared with other 3D printing technologies.

However, the advantages, for the most part, won’t be realized until there are fundamental changes in the way material properties are specified and in the predictive sciences.

Industry will not capitalize on these material advantages until it ceases to specify material properties based on what is already available. 3D printing will explode when engineers begin to specify properties available only through the additive processes, especially properties that may vary throughout a part (functionally graded).

As long as 3D printing is viewed as a direct replacement that must match the deliverable properties of conventionally made parts, it will see only modest growth.

But there is a chicken-and-egg element. Before engineers specify these new properties, they must be able to predict the performance. This means that we need the science to characterize and quantify the mechanical, thermal and electrical properties. When asked why they limited users to 90 discrete Digital Materials, Objet replied that users need to know the properties, which isn’t possible when they can create an infinite number of custom blends.

So, 3D printer material properties are only a weakness because science has not caught up to the opportunity. But just give it time — it will, and when it does, 3D printing will really take off.