R. Johe, EUROFLEX, Pforzheim, Germany
During tensile testing of superelastic nitinol material the specimen warms up itself as result of the exotherm austenite-to-martensite transformation.
This increase in specimen temperature has great influence on the mechanical properties - in particular upper and lower plateau - and limits the strain rate of the tensile test.
A special setup of the tensile testing machine using a fan to remove the heat out of the specimen allows much more higher strain rates with also flat run of the upper and lower plateau.
A comparison study of tensile testing according to ASTM F 2516 vs. tensile testing with higher
strain rates with focus on upper and lower plateau values dependeding on Af temperature is done.
Summary: During tensile testing of superelastic nitinol material the specimen warms up itself as result of the exotherm austenite-to-martensite transformation.
This increase in specimen temperature has great influence on the mechanical properties - in particular upper and lower plateau - and limits the strain rate of the tensile test.
A special setup of the tensile testing machine using a fan to remove the heat out of the specimen allows much more higher strain rates with also flat run of the upper and lower plateau.
A comparison study of tensile testing according to ASTM F 2516 vs. tensile testing with higher
strain rates with focus on upper and lower plateau values dependeding on Af temperature is done.
