Note: Heat setting of Nitinol

To heat a 0.005 in (0.13 mm) diameter Nitinol wire for a shape setting application 

Nitinol wire

Ambrell 2 kW induction heating system equipped with a remote heat station containing two 0.33 μF capacitors (total 0.66 μF).
An induction heating coil designed and developed specifically for this application.

Nitinol wire
Steel fixture 

930 °F (500 °C)

190 kHz

The customer-supplied fixture consists of two concentric cylinders: a 0.1 in (2.54 mm) thick hollow outer cylinder is slipped over a 1 in (25.4 mm) diameter solid cylinder. The required Nitinol shape is etched on the OD of the inner cylinder. The solid steel fixture supplied is modified to reduce the thermal mass. The solid inner cylinder is drilled to allow for a coil to be inserted in the ID. A special four-turn internal and external helical coil is used to generate the required heat pattern. Initial tests are conducted (using a thermocouple) on a fixture without a part to establish the heating cycle. The part is placed into the fixture and the induction-heating coil over the part. Power is supplied until the part is heated to the set point and is held at this temperature for 2.5 minutes. The fixture is immediately quenched in water following  the heat cycle. Parts are made to the specifications for shape memory