Home > Applications > Heat Setting

Heat Setting Nitinol Medical Stents

Heat setting nitinol medical stentsResearch Objective
Heat setting medical stents on mandrel to set proper size is the objective of this induction heating application.

Parts & Materials Description
Nitinol metal stents, 5mm x 150mm mandrel

Temperature Required
510°C +/- 2°

Induction Heating Equipment
1kW RF power supply and a .66 microfarad heat station, 9 turn round inductor (coil), fixture to hold 5 x 150mm mandrel, AE optical pyrometer, water quench tub.

Operating Frequency
197 kHz

Heating Procedure
This heat treating process required very precise temperature control. The temperature could not very over 2 degrees along the length of the mandrel.

The stent was slid onto the mandrel and the mandrel placed into the inductor. The power was set to ramp up to 510°C in 2 minutes so that the temperature across the mandrel remained relatively even. As set point temperature is reached, the mandrel was held for 2 to 3 minutes. The part was then removed from the inductor and quenched in water.

Conclusion
The stents heated very well on the mandrel. The ramp up rate was minimized to 2 minutes to avoid over heating at the ends of the zones. After the mandrel/stent was quenched, the stent would easily slide off the mandrel by itself.

GH IA logo

Innovative Induction Heating

induction heating solutions