Polymer-Derived Ceramics Thin-Film Plasma Anemometer With High Resistance to Plasma Sputtering

Due to the poor plasma sputtering resistance of PVD thin-film plasma anemometer electrodes, the working life of the sensor is short and the repeatability of the output signal is poor, which greatly restricts the practical process of the plasma thin-film anemometer. Polymer-derived ceramics (PDCs) have excellent high-temperature mechanical properties, high-temperature stability, oxidation resistance, electrical properties, and superior processing and molding characteristics, which is expected to solve the above problem. In this article, we use PDCs to prepare plasma thin-film anemometers, and carry out a comparison experiment with PVD thin-film plasma anemometer. The results show that the PDCs thin-film plasma anemometer has better sputtering resistance, and can continue to work for more than 2.5 h at a current of $7\sim 8$ mA, and the signal fluctuation does not exceed 2.48%. Its high-temperature resistance is up to $900~^{\circ }$ C. In addition, we carried out static calibration and repeatability tests on the PDCs thin-film plasma anemometer. The speed measurement range can reach 150 m/s on the alumina substrate with a sensitivity of $16.7~\mu $ A/(m/s). After six rounds of outbound and return repeated tests, the error is controlled within 5%. By using PDCs process to prepare a plasma thin-film anemometer, the working life and signal repeatability of the sensor are greatly improved, which provides an important support for the development of a plasma thin-film anemometer.