Thad Vreeland Jr., emeritus professor of materials science at the California Institute of Technology (Caltech), passed away August 9, 2010, 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.  In the 1960s and '70s, 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.  His work in the 1990s included studies of how powders can be consolidated into bulk materials by subjecting them to strong mechanical shocks.  He took pride in laboratory technique and had both skill and style in building his own equipment.

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.

"Thad was a great scientist and he interacted well with various researchers and engineers across campus," said Ares Rosakis, chair of the Division of Engineering and Applied Science, "particularly with the solid mechanics group associated both with aeronautics and mechanical engineering."

Thad 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.  Lots of Caltech faculty and students came up to fish with him."

In addition to Mary, Thad is survived by his children, Michael, Terry, and Janet; and two grandchildren, Theresa and Johanna.

Caltech Media Relations, October 8, 2010