Thad Vreeland Jr., emeritus professor of materials science at the California Institute of Technology (Caltech), passed away August 9 in San Gabriel, California. He was 85 years old.
Vreeland—a member of Caltech's materials science program from its earliest days—was best known for his studies of the mechanical properties of materials, with an emphasis on how severely stressed materials deform plastically and permanently.
"His specialty was defects in materials—specifically dislocations, which are the agents of plastic deformation," says Brent Fultz, professor of materials science and applied physics at Caltech, and one of Vreeland's colleagues.
In the 1960s and '70s, Fultz says, Vreeland performed challenging experiments to measure how fast dislocations move in metal crystals; in the '80s, he studied how defects in thin layers of semiconductor materials are generated by ion bombardment or stresses. Vreeland's work in the 1990s included studies of how powders can be consolidated into bulk materials by subjecting them to strong mechanical shocks.
"Thad Vreeland took pride in laboratory technique and had both skill and style in building his own equipment, often frugally," says Fultz. "With the University of Pennsylvania's David Pope—then a Caltech graduate student—Vreeland designed and built a device for subjecting large crystals to pulsed torsional loads, and he built several x-ray diffractometers of unique design. Thad Vreeland's shock wave consolidation facility used the barrel of a field gun that he reinforced for even higher velocities."
Vreeland worked as a consultant for organizations such as Union Carbide, and collaborated with corporations and research institutions such as the McDonnell Douglas Research Laboratory on varied materials projects. He coauthored The Analysis of Stress and Deformation with Caltech's George W. Housner, who passed away in 2008.
"Thad was a great scientist and he interacted well with various researchers and engineers across campus," says Ares Rosakis, the Theodore von Kármán Professor of Aeronautics, professor of mechanical engineering, and chair of the Division of Engineering and Applied Science, "particularly with the solid mechanics group associated both with aeronautics and mechanical engineering."
Vreeland was born in 1924 and was a lifelong member of the Caltech community, receiving his BS in 1949, his MS in 1950, and his PhD in 1952. That same year, he was named a research fellow in engineering; he subsequently joined the Caltech faculty in 1954 as an assistant professor of mechanical engineering. Vreeland was a professor of materials science from 1968 until his retirement in 1991, whereupon he was named emeritus professor.
After his retirement, Vreeland spent a great deal of time in his Montana home—most of which he designed himself, says his wife, Mary Vreeland. "It was near West Yellowstone, which is the trout fishing center of the west," she adds. "Lots of Caltech faculty and students came up to fish with him."
In addition to Mary, Vreeland is survived by his children—Michael, Terry, and Janet—and two grandchildren, Theresa and Johanna.
