NiTi rods

Two nickel-titanium rods of slightly different composition are shown. One is in the high-temperature form at room temperature and the other is in the low-temperature form. The latter is easily bent, but the former is not. Cooling the stiff, high-temperature-phase rod into its low temperature form makes it easier to bend. As it warms back to room temperature, the rod straightens. A heat gun is used to straighten the other, low-temperature-phase rod. (Companion Demonstration 9.4)