A team of students and professors from South Dakota Mines assisted Air Force personnel in
employing cold spray technology to repair a
broken hinge tied to the fuselage of a B-1B Lancer. Cold spray, an
additive manufacturing method, is essentially spray on metal that can be
machined to fit. The technology uses metal microparticles that are sprayed at
very high velocities. These tiny particles then adhere to the original metal on
impact, forming a dense coating or deposition. In many cases, cold spray can be
used to restore worn and damaged aircraft parts to extend service lifetimes.
Without cold spray technology, the fix of this B-1 would
have required a lengthy repair process and a cost estimated to exceed a half of
a million dollars which would have included dismantling part of the aircraft
and sourcing spare parts from a salvaged bomber.
“This would have normally involved eight weeks of
downtime. With cold spray we were able to do this in a couple of hours,” said
Brian James, a Ph.D. graduate student at Mines, and a chief engineer with the
28th Maintenance Group at Ellsworth Air Force Base. James is part of a team
inside the 15,000 square foot Additive Manufacturing Facility at Ellsworth. He
added this technology is a game changer for aircraft maintenance.
James says the innovative repair of this B-1 is 14
years in the making. It started in the mid-2000’s with research into cold spray
technology at Mines that sought to find better ways to restore obsolete and
legacy aircraft components. As the research and development progressed over the
years, it led to spin-off companies and the addition of the additive
manufacturing technology to the toolbox of the 28th Maintenance Group. “This facility at Ellsworth is the first of
its type,” said James. “What we are doing here is taking technology that’s been
tested and proven in the lab and infusing it right at the combat level.”
James noted there is a long list of individuals,
organization and industry partners, political leaders who have helped make the
program successful, including Dr. Heather Wilson, former Secretary of the Air
Force and Mines president, industry partners like VRC Metal Systems, Army and
Air Force Research Laboratories, and numerous Mines students and professors who
have contributed hard work and expertise over the years.
“The school has been a huge supporter, especially
Dr. Grant Crawford who helps us come up with solutions to problems we have
encountered on the way,” James said. “More
recently the addition of the X-Force Fellowship program
though the National Security Innovation Network is bringing young innovators to
the table,” James added.
Zac Hogan, a mechanical engineering major and an
X-Force fellow from Mines, is the latest edition to Ellsworth’s additive manufacturing
team. “It’s wonderful to work on real-world problems and there is a creative
freedom in the approach here,” Hogan said. “What they are interested in is problem
solving and how we go about it is up to us. We attack the problem from every
perspective, and we work to make sure we are utilizing all the resources
available in finding solutions.”
Hogan is working with X-Force fellows from
universities around the country on the project. “Zac has been a huge benefit to
the program, he has brought a fantastic work ethic and fantastic problem
solving to the team,” said James.
The work of this team is showing that the employment
of cold spray technology improves combat readiness of legacy systems like the B-1.
David Darling who spent 26 years in the Air Force maintenance is the site lead
at the Ellsworth Additive Manufacturing Facility. He says the array of testing
equipment at Ellsworth’s Additive Manufacturing Facility can be used to
demonstrate the strength of any repair. “We have a full lab including a
scanning electron microscope, hardness testers, tinsel testing, and other
equipment,” Darling said. “So, within hours after application we can see test
results that show our success."
For the Air Force, cold spray increases the lifespan
of a weapons system, and for maintenance personnel on the ground, the
technology offers a new highly cost-effective tool that revolutionizes repair
of critical aircraft components. Staff Sgt. Chynna Patterson, a machinist and
welder assigned to the 28th Maintenance Squadron at Ellsworth, spent 10 years
working on other aircraft like the A-10 Warthog. “This technology allows us to
maintain the aircraft in ways that would previously have been very time consuming
and very expensive,” she said. Patterson said she believes additive
manufacturing and cold spray can be used on other aircraft systems Air Force
wide. “Learning all the applications of this technology has been wonderful,”
she added.