Field Intelligence guest column
What do Hanwha Power Systems and Mohawk Innovative Technology have in common? Each company stepped out on the edge and, in pursuing their best, most aggressive designs, decided not to accept the conventions and limits of Design for AM (DfAM).
DfAM is practiced broadly in industry and academia today in the form of imposing manufacturing constraints on design ambitions. The set of practices has turned into an acceptance of the status quo, a facet of the very “build” process software itself, and an acknowledgment of what most often can’t be done with conventional Laser-Powder Bed Fusion (LPBF).
AM is meant to break paradigms. But, quietly, the real-world constraints on AM are being downplayed for what the technology can do against machining, casting and other methods. AM has made a significant impact on how we think about the possibilities of design and manufacturing. Yet much more development has to take place for metal AM to align with high-performance, conceptual design.
Why am I calling out DfAM and not the broader industrial category of Design for Manufacturing (DfM)? In the semiconductor industry, rule-based and then model-based DfM went hand-in-hand with a relentless drive to expand the limits of the manufacturing technology. DfM was not a replacement for advances in manufacturing technology; DfM complemented it.
DfAM today is mostly a construct to compensate for the weaknesses of LPBF. Weaknesses that were set in the last century and stand today where they were back then. DfAM often involves designing the part in ways that will alleviate the need for supports in places that those supports would not be practical to remove, or will prevent the achievement of acceptable surface quality.
Now, imagine a world where walls and internal channels include a design space from zero to 180 degrees instead of stopping at 45-degree angles like DfAM tells us we must. The companies mentioned above used Velo3D’s AM tech to produce remarkable product advances and far-reaching end benefits.
For the U.S. Department of Energy (DoE), Hanwha developed a shrouded impeller utilizing supercritical carbon dioxide (sCO2) to drive an advanced Concentrated Solar Power Array. Here, what they called “huge geometric freedom” was made possible by the capabilities of the Velo3D system, with its end-to-end process and quality controls. This let engineers imagine and deliver fully enclosed, low-angle, sweeping blades, made from a challenging-to-work-with, high-performance nickel alloy—3D printed completely without supports.
Mohawk, working on a different type of sCO2 system for a DoE solar-power project, used Velo3D to achieve what they themselves called a “pretty strange” solution, with complex geometries that addressed different fluid-flow and temperature forces inside the curved channels of volutes. The support-free interior walls were printed at such high quality that performance was greatly enhanced, and at a cost savings of two-and-a-half times that of making such a component using traditional methods.
In both companies’ cases, engineers were able to realize the novel solutions they imagined, rather than workarounds based on what they’d previously been able to achieve. It’s time to redefine AM and DfAM by what is now possible from advanced LPBF systems—and to look ahead with the same dedication and determination that the semiconductor industry used to better our lives.