Manmade materials positively impact our world in countless ways. They also determine, to some degree, the sustainability of a given product. Whether or not a material is toxic, is extracted from the earth (as opposed to grown), is energy intensive to produce or, perhaps most important of all, how well it performs its function all determine the type of impact it has on the world.
As a result, material science plays an increasingly significant role in product development as businesses focus on sustainability. Developments in this field have produced materials that are lighter and stronger, as well as those that require less energy to move, ushering in a raft of portable electronic items like cell phones that are both smaller and more powerful than their predecessors.
However, some of the materials in those products are rare earth metals that are considered irreplaceable. While phones only use tiny amounts of rare earths, larger products, like jet engines, require quite a bit more. For an industry poised for significant growth, that could be a problem from a sustainability perspective.
United Technologies Research Center (UTRC), the innovation hub of United Technologies Corp., set out to explore whether 3-D printing could be used to produce a 30-kilowatt induction motor that does not rely on rare earth magnets. The research was conducted under the Department of Energy’s Advanced Research Project Agency-Energy (ARPA-E) program, alongside partners from the Connecticut Center for Advanced Technology (CCAT), Ricardo, Inc. and Pennsylvania State University.
The group proposed to produce copper conductors, dielectric components, and steel laminations using a single additive manufacturing system, explained Wayde Schmidt, group leader in UTRC’s Applied Physics group of the Physical Sciences department.
At the end of the day, the UTRC-led team had some successes and some challenges. Copper strands proved relatively easy to produce using laser sintering methods developed by a contracted vendor, while integrating multiple materials into one manufacturing process proved more difficult and remains a necessary challenge to overcome.
United Technologies has worked with 3-D printing technologies, also known as “additive manufacturing” since the 1980s, beginning with plastics and more recently focusing on metals for structural applications. They also use something called “topology optimization methods,” where design software predicts the exact stress patterns to be expected in a part when it is deployed. While United Technologies focuses primarily on industrial products, consumer products have also begun to utilize these breakthroughs. Under Armour is using similar technology to create a 3-D printed shoe, known as the Architech, which was inspired by the internal trabecular structure found in human bones that allow for lightweight flexible strength.
So companies have shown the usefulness of this innovation, but when Schmidt cautions that while design software can precisely define the stress level at each point in an object, and further suggest an appropriate cross-section to be used there, not enough is yet known about how the materials produced in this way will behave under real world conditions. More testing is still needed. It’s one thing for the support of an athletic shoe to momentarily fall outside of its design window, and another thing entirely for a turbine blade in a jet engine to operate outside of its design specifications.
Speaking of which, when I asked Schmidt if these materials can help improve sustainability he told me about the considerable amount of work that has gone into the materials used in Pratt & Whitney’s jet engines.
A simple rule in this arena is that higher temperature operation means better fuel economy; however, most traditionally manufactured materials cannot stand up to high temperatures for very long. United Technologies, Pratt & Whitney’s parent company, has developed a number of metal matrix and ceramic-matrix composite materials, as well as super alloys and thermal shock-resistant coatings designed specifically for those conditions. Nanotechnology is another area where much new ground is being broken. Schmidt said United Technologies is using it in a variety of ways including coatings for optical applications, thermal and environmental protection, and reinforcements in composites.
In the area of intelligent building systems, served by Carrier and other brands of UTC Climate, Controls & Security, there is ongoing research on advanced refrigerants, plastic heat exchangers, frost free coatings and strategies to reduce or prevent corrosion of metallic components.
Accomplishing all that with materials that are environmentally safe is a big challenge. UTRC won two Green Technology Innovation awards in 2014 from R&D Magazine. One award was for its EcoTuff corrosion inhibitor coating, which eliminated the need for hexavalent chromium, a known carcinogen. The second was for a portable aluminum deposition system (PADS), the first green electroplating system of its type, which is used both for repairs and for corrosion resistance on structural metal parts.
There can be no doubt that we will continue to see significant advances in materials that will allow for the creation of products that we can’t even begin to imagine today.
Image courtesy of United Technologies (press use only)