After Marquis Scholar Ryan Waite ’05 (Lebanon, Pa.) completes the cutting-edge research in his senior honors thesis, a serious engineering problem will be better understood.
His project will enable engineers to accurately test the phenomenon known as galling, wear that occurs in metal-to-metal contact. The biomedical field will benefit most from Waite’s work, which he hopes will prolong the life of expensive operating room equipment.
The mechanical engineering major is assembling, modifying, and validating the galling machine created by Lafayette students as a senior design project last year. The machine was originally built to automate the galling resistance test method.
“Galling is adhesion and tearing that comes from non-lubricated metal-to-metal contact,” explains Scott Hummel, associate professor of mechanical engineering and Waite’s adviser.
Unlike scratching, which Hummel describes as abrasive wear, galling is an extreme case of adhesive wear.
Owner of two U.S. patents, Hummel teaches courses in mechanical design and manufacturing and advises students who are researching galling in stainless steel. Their results have been published in Tribology International and Wear and presented at the American Society for Testing and Materials (ASTM) Committee Week conference. Hummel was awarded a National Science Foundation grant and appointed chairman of a Galling Resistance Test Review Task Group by the ASTM Subcommittee on Non-Abrasive Wear. The ASTM is reviewing his line contact test for galling resistance testing methods to consider making it an alternative form of standardization.
Exactly how galling occurs is not known. The accepted test for it was discovered during research completed at Lafayette two years ago, but it needs improvement. The purpose of the new Lafayette prototype machine that Waite is improving is to obtain more precise results.
“I’m making several design modifications,” he says. “These will create a more user-friendly interface. In addition to making the machine functional, it also needs to be interfaced to a computer to collect data such as applied force, torque, and speed. I am also redesigning the contact region of the two test specimens, which will give a more uniform stress distribution.”
Designing a test machine that more accurately replicates what happens when two metals slide against each other will not only help engineers and designers increase their knowledge of galling, it will enable them to select metal types more resistant to the frictional stresses. According to Hummel, the project is state-of-the-art.
Equipment used in orthopedic surgery is particularly susceptible to galling. The instruments that insert and extract implants such as bone screws and hip and knee replacements must exert tremendous force on the implants. When the contact surface on the instrument experiences galling, a very expensive and critical piece of medical equipment is rendered inoperable.
Since stainless steel is used primarily in surgery for its strength and biocompatibility, the Lafayette machine will also enable designers to select two types of stainless steel – one for the implant and one for the instrumentation – that resist galling.
“The project means a lot to me because this particular area of metal-on-metal wear is relatively unknown,” says Waite. “Unlike a lot of other areas in engineering, designing against galling or characterizing galling resistance does not have a straightforward recipe. That’s the exciting aspect, working on discovering how galling occurs and how we can prevent it from presenting design problems.”
Waite credits Hummel with guiding him on this project and deepening his interest in engineering.
“He’s been able to answer many of my questions about engineering in general and my personal career goals,” says Waite, who previously worked with Hummel through Lafayette’s EXCEL Scholars program, in which students conduct research with faculty while earning a stipend. “The work I have done with him has not only been rewarding in a scientific sense, it has also gone a long way in reaffirming my desire to enter the field of engineering.”
Waite, who plans on pursuing a master’s degree in aerospace engineering after graduation, gives credit to Lafayette for grooming his engineering talents.
“It’s been a good environment for my project because I often get one-on-one time with my adviser, and I have been working in a lab that I pretty much have to myself,” he says. “The machines are always available for help and the machine shop staff have helped me whenever I need anything.
“Mechanical engineering at Lafayette has been a good choice for me because I have enjoyed the mix of hands-on experience and theory. During my four years, mechanical engineering has grown rapidly and changes have been made to the curriculum that I think will make the program even stronger. The department did a very good job preparing me with a well-rounded engineering education that allows graduates to go in any direction they want.”
Waite is vice president of the Tau Beta Pi engineering honor society, secretary of the student chapter of the American Society of Mechanical Engineers, and vice president of men’s club volleyball. He also is a member of Arts Society and has served as a writing associate. He graduated from Cedar Crest High School.
Chosen from among Lafayette’s most promising applicants, Marquis Scholars such as Waite receive special financial aid and distinctive educational experiences and benefits, including a three-week, Lafayette-funded study-abroad course during January’s interim session between semesters. Marquis Scholars also participate in cultural activities in major cities and on campus, and mentoring programs with Lafayette faculty.
Honors thesis projects are among several major opportunities at Lafayette that make the College a national leader in undergraduate research. Lafayette sends one of the largest contingents to the National Conference on Undergraduate Research each year. Forty-two students were accepted to present their work at the last annual conference in April.