Model and Design of High-Temperature Ultrasonic Sensors for Detecting Position and Temperature Based on Iron-Based Magnetostrictive Wires

Fe ₃₀ Co ₇₀ , Fe ₈₂ Ga _13.5 Al _4.5 , and (Fe ₈₃ Ga ₁₇ ) _99.4 B _0.6 magnetostrictive wires with improved magnetostrictive value and high Curie temperature have been successfully prepared. These wires can be used in the design of magnetostrictive ultrasonic sensors (MUS) for position and temperature detection over a wide temperature range. The signal intensity model is established under non-adiabatic conditions based on the thermodynamic laws, the magnetoelastic coupling effect, the Boltzmann statistics and the inverse magnetostrictive effect. Position sensor up to 500 °C and temperature sensor up to 1200 °C were designed with optimal operating parameters according to the model and properties of magnetostrictive wires. The output signals are reliable at intensity and noise level, ready for the stable working of sensors at room and elevated temperature. The two kinds of MUS presented in this work have advantages of high upper limit of working temperature and non-contact, which are suitable for harsh environment applications.