The Thermal Resistance Performance of WTi Alloy-Thin-Film Temperature Sensors Prepared by Magnetron Sputtering

The microstructure and properties of WTi alloy films with 0~23 at.% Ti prepared by magnetron sputtering were investigated. The electrical resistivity gradually increased with the increase in the Ti content. When the Ti content was 6.8 at.%, the temperature coefficient of resistance of the alloy film reached the maximum value of 19.5 × 10−4 K−1, which is 3.6 times higher than that of the pure W film. After several thermal resistance tests, the temperature coefficient of resistance of the WTi alloy film with 6.8 at.% Ti decreased gradually. After five measurements, the temperature coefficient of resistance decreased gradually from 19.5 × 10−4 to 16.3 × 10−4 K−1. After annealing at 500 °C for 30 min, the grain size of the WTi alloy film (6.8 at.% Ti) increased, a few pores appeared, and the density of the film decreased. The temperature coefficient of resistance decreased from 19.5 × 10−4 K−1 to 14 × 10−4 K−1. When the annealing time was increased to 60 min, the structure and properties of the WTi alloy film remained basically unchanged. After conducting the annealing treatment for 30 min, the WTi films showed excellent stability in the thermal resistance tests, and their temperature coefficient of resistance was basically consistent after cyclic thermal loading, which has promising application prospects for the temperature measurement of tools and dies.