McCormick Magazine

Grand alliances

Ford-Boeing partnership fuels research


shull and denolfWhen a new automobile or commercial aircraft rolls off the line, its paint — the slick sheen that ranges from bright blues to burnt oranges — is actually a multitude of layers applied through a multistep process. How well those layers stick to each other — and how to measure how well they stick — is an area where research so far has been imprecise. But now, under a new kind of agreement with Ford Motor Company and the Boeing Company, McCormick researchers hope to find the best way to measure paint adhesion.

In October 2005 Ford and Boeing signed a three-year agreement to establish funding for Northwestern researchers to study nanocomposites, specialty metals, thermal materials, coatings, and sensors. With stagnant federal research funding and the changing nature of research and development, the McCormick School has thrived by creating research agreements like these with some of the top companies in the nation. These partnerships give faculty members the means to pursue research in their areas of expertise and allow companies to reap the benefits of that research. McCormick’s Office of Corporate Relations has overseen such agreements with Ford and Boeing and with Honeywell International.

“A fluid partnership with corporate partners is critical due to major changes at multiple levels: the changing nature of federal funding and R and D funding within major corporations and a much higher level of entrepreneurship among faculty and students,” says Dean Julio M. Ottino.

When Ken Shull, professor of materials science and engineering, learned of the agreement, he was immediately interested since his primary research lies in adhesion. “Paint adhesion was one of the things Boeing and Ford cared about, and we had some ideas based on other adhesion experiments we were doing,” he says.

Under the agreement, Shull and graduate student Garret DeNolf have proposed developing new ways to determine how well a paint sticks to a surface. The pair has developed a new membrane-contact method that quantifies the adhesion of paint layers to different surfaces. In this method, Shull and DeNolf apply a layer of paint to a thin, flexible membrane, then push the membrane into contact with a particular surface. After the paint cures, researchers can measure the adhesion of the paint by peeling off the paint layer.

Shull and DeNolf are also using a nondestructive test of adhesion using acoustic waves. This sort of testing is often used in structural analysis, and Shull thought it might also work to see whether a coating had stuck well to either metal or a previous coat of paint. “It’s like an ultrasound that can see if there is an internal crack in the paint,” Shull says.

The process uses the vibrations of a quartz crystal to determine how paint layers — which are usually 20 to 100 microns thick — have stuck to a surface. Sometimes engineers have trouble making the first coat of paint stick to a metal, and sometimes the second coat won’t stick to the first. “If you have paint flaking off your car, that’s a huge problem for a company that’s selling that car by the thousands,” Shull says.

While engineers at Ford and Boeing certainly understand the dynamics of paint adhesion, there can be a lot of variables. Paint applied in humid Alabama, for example, might act differently than paint applied in dry Arizona. “They don’t know exactly why paint acts differently in different circumstances, and that’s what we’re best at answering,” Shull says. “We’re driven by intellectual curiosity, so figuring out these problems is a good fit for us. We can make a connection between how these paint coatings are behaving and how they fail based on what we measured during the curing process. There aren’t any good tests yet to really quantify adhesion with the precision that we need.”

Shull and DeNolf, who will continue working on the project through 2009, say the project brings new goals and new chances to work with engineers in the field. “I like working with industrial collaborators because they have a good sense of what is of practical value,” Shull says.

DeNolf, who has been giving Ford and Boeing monthly updates on the project, says such timelines have given him a good look at how the research is progressing. “It keeps you moving, and it really shows the application of the research,” he says.

—Emily Ayshford