Above: Rolls-Royce operator Richard Warren prepares to fit a C47B/8 turbine onto a M250-C47B/8 engine, at the company’s Indianapolis factory.

Rolls-Royce joins Purdue University in fostering aerospace research

November 2015 - Purdue University in West Lafayette, Indiana, has an illustrious history of educating future aeronautics engineers, pilots and astronauts, and of working with businesses to link the brightest students with the highest flying companies.

The Purdue Research Foundation announced in late September that jet engine manufacturer Rolls-Royce, which operates an expanding factory complex in Indianapolis (see sidebar), became its first partner in the Purdue Research Park Aerospace District. The foundation plans to build a 40,000-square-foot facility in the district to house the research and development group for Rolls-Royce and for other companies interested in aerospace and aviation development.

Creating the district “is a way to package assets and present them to the world,” says Dan Hasler, president of Purdue Research Foundation and Indiana’s former commerce secretary. “Look at Purdue aeronautics history. The first airmail flight was in West Lafayette. Amelia Earhart kept her plane here,” says Hasler. “Twenty-three astronauts—[serving on] one-third of all NASA missions—were Purdue graduates. We have an aerospace and aeronautics program that is killer.”

The university has a parcel of land adjacent to its own airport, and decided it should “be reserved for a special purpose,” he says, adding that Purdue possesses assets that few academic institutions can offer. “We already have a Mach 6 wind tunnel. Companies come there all the time to do their testing. We have propulsion and rocketry laboratories. That’s one of the reasons Rolls-Royce was interested in being among the first occupants.”

R&D center employees will perform component design and testing of jet engines, Hasler says. “It will occupy undergraduate and postdoctoral  students looking for educational projects.”

About 250 companies cluster around Purdue because “they know there are 40,000 scary-smart students here, and thousands of engineering faculty doing research on disruptive technologies, and they cannot afford to miss out on that talent.”

Although sequestration has curtailed defense spending, “we are seeing the privatization of space travel and incredible activity in drone engineering and manufacturing, including for agricultural applications,” says Hasler, “so there are a lot of different vectors” for aerospace industry growth. 

Dennis Warner, an executive for Rolls-Royce, says the aerospace district deal is an expansion of the work it already does with and through Purdue. 

“This concept is like another we use at [Purdue’s Maurice J.] Zucrow Laboratories, where we do casting. We have engineers going to Purdue to have dedicated office space and master’s and Ph.D. students work with us on research and development,” Warner says. R&D center staff will include engineering and technology students, even business management students, he adds. The work will initially involve mechanical system testing, mostly likely for fuel pumps, fuel metering systems and, “in the future, perhaps some electronic devices.” Warner hopes to have the center operational by the last quarter of 2016. 

Twenty years ago, Purdue was the first U.S. university to be named a Rolls-Royce university technology center, and it is part of a global network of top engineering and aviation institutions the company partners with to conduct research, including Virginia Tech and University of Virginia. Rolls-Royce employs about 600 Purdue graduates. “Purdue is a talent pipeline,” says Warner.

Talent for metallics

A critical part of research and development for jet engines and hundreds of other aerospace parts and components is how materials perform under all sorts of stresses, including extreme heat.

Matthew Krane, a professor of materials engineering, says that students at Purdue’s Center for Metal Casting Research study all phases of metals production: melting, casting, quenching, reheating, rolling, forging, extruding, shaping, machining, coating and more.

“We work on a wide range of processing and fundamental applications. We do shape casting, investment and die casting. We look at the solidification process of wrought metal,” says Krane. “When you use shape casting, that material may look right but what happens after machining and other processes?” 

The metals research has touched on direct chill casting of aluminum alloys, electroslag remelting of nickel-based alloys (“Rolls-Royce uses them,” says Krane), plus vacuum arc remelting of titanium and continuous casting of steel. 

The number of Purdue’s metals research projects are “actually growing. We just hired another metallurgist.” Metals companies that have worked with faculty and graduate researchers on specific projects include Novelis, ArcelorMittal, Haynes International, Alcoa Inc., Alcoa Howmet, Special Metals Corp., U.S. Steel Co. and Precision Castparts Corp.

Exotic equipment

Among the testing equipment the center uses—all of which are detailed at www.purduecasting.org—is a levitation zone melter. Levitation zone melting is a containerless processing method for high-temperature, high-purity alloys and compounds. The equipment uses induction power to heat, levitate and constrain the molten zone in order to treat it as an open chemical system where selected chemical reactions can obtain desired purity levels.

In addition to a 28-ton vertical die casting machine and vacuum induction furnace, Krane says the center is “taking delivery this fall of a single-crystal investment casting furnace. It’s a pilot scale furnace” with which Purdue researchers will attempt to determine how to produce single-crystal turbine blades to use in the hottest stage of jet engine function. “The first few stages have the hottest gases, highest temperatures, making complicated shapes as a single crystal difficult. We plan to use [the findings] as part of a project with Rolls-Royce,” Krane notes.

Micro-segregation

The metal casting center’s work is meant to answer critical questions for potential applications. For example, “we did one project for an aluminum application but the procedure could be used with other alloys and processes and customers,” says Krane.

“We looked at the casting of an alloy via direct chill casting and had students try to predict segregation. The questions we wanted to answer were: How much segregation can you live with and what do you do to lower segregation? 

“We researched what the real constraints are and determined the line where the material fails in service or in downstream processing. If you can make an ingot but cannot extrude it or forge it, then what’s the process worth?”

If metals producers can perfect the material’s chemical and mechanical consistency at the micro-segregation level, says Krane, “it’s right there where we have the most control over the structure.” Then the material can proceed through heat treating, shaping and bending and yet remain in a state that will resist defects in critical applications.

Krane says students “predicted segregation by initial composition, coolings rates and casting speed. They got rid of small-scale segregation with homogenization (heat treating) and conducted experiments to understand the homogenization process in different parts of ingots, even with differential rates of cooling and grain sizes.”

Many, many tests were conducted “to find uniformity and how much non-uniformity is acceptable, versus the costs of aiming for uniformity.” After all that, Purdue was able to recommend what the metal producer should do during metalforming processes to get the material to achieve repeatable commercial success.

Fresh eyes

“Academics can ask questions and make an impact,” Krane says. “When we work with industry we bring a fresh set of eyes. Our job is not getting metal out the door but researching what they don’t have time for,” and eventually, that work helps them to do their jobs better.

What companies do with the knowledge varies. “Sometimes they say thanks very much, or they implement the knowledge.”

Although there is a strong emphasis on solving real-world industrial problems, Krane says the center also conducts experiments that are “more theoretical,” and may have practical applications down the road. Professors and students will try out “crazy ideas,” and then apply for patents, which later generate interest from industry. MM

Web exclusive: Purdue researchers are trying to find a low-cost way to create a low-energy plasma field over wings so that air can be lifted 30 to 50 percent more efficiently. It could work on windmill blades and marine propellers, too. Learn more about it at www.modernmetals.com/plasmafield.