The Story of Nitinol: The Serendipitous Discovery of the Memory Metal and Its Application

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 2 Issue 2 (1997), S1430-4171(97)02111-0

The Story of Nitinol: The Serendipitous Discovery of the Memory Metal and Its Application

George B. Kauffman* and Isaac Mayo

California State University, Fresno, CA 93740-0070

and College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401

Published online: 26 June 1997

Abstract. The shape-retaining alloy Nitinol (Nickel Titanium Naval Ordance Laboratory), the "metal with a memory," is revolutionizing manufacturing, engineering, and medicine as countless products that "think" for themselves enter the marketplace. This article recounts its discovery in 1959 by William J. Buehler of the U.S. Naval Ordnance Laboratory, its subsequent development by Buehler and Frederick E. Wang, and its applications in orthopedic and cardiovascular surger, orthodontics, solid-state heat engines, "shrink-to-fit" pipe couplers for aircraft, safety products, eyeglass frames, and toys. The serendipitous nature of the discovery, the solid-to-solid (austenite to martensite) phase transition that produces the alloy’s unusual properties, its numerous practical applications, and the ready availability of samples make the alloy an ideal, exciting, and thought-provoking topic for chemistry courses at all levels in both lecture and laboratory.

Key Words: Chemistry and History; Nitinol; alloys; austenite; commercial applications; cyrstallography; "intelligent metals;" laboratory demonstrations; lecture demonstrations; martensite; "memory metal"; metallurgy; metals; phase transitions; research and development; serendipity; solid state devices

(*) Corresponding author. (E-mail: george_kauffman@csufresno.edu)

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