F. Sczerzenie, G. Paul, C. Belden, SAES Smart Materials, New Hartford, NY; A. Fasching, Memry Corporation, Menlo Park, CA
Inclusion content is important for the mechanical behavior and performance of Nitinol wires particularly in fatigue rated devices. The primary inclusions in VIM-VAR Nitinol are carbides formed on solidification. The secondary inclusions are intermetallic oxides formed during thermo-mechanical processing.
This study measured the carbide and oxide inclusions separately using optical metallography and scanning electron microscopy. A comparison was made between these separate populations in cold drawn wire and the precursor populations in hot rolled rod coil from the same coil. This work provides a better understanding of the differences in behavior between carbides and intermetallic oxides in wire drawing and the implications for wire performance.
Summary: Inclusion content is important for the mechanical behavior and performance of Nitinol wires particularly in fatigue rated devices.
This study measured the carbide and oxide inclusions separately using optical metallography and scanning electron microscopy. A comparison was made between these separate populations in cold drawn wire and the primary populations in hot rolled rod from the same coil.
This work provides a better understanding of the differences in behavior between carbides and intermetallic oxides in wire drawing and the implications for wire performance.
