Temperature stability of elasticity moduli for piezoceramics

Abstract

The temperature dependences of elasticity and shear moduli for TsTBS-3 and TsTSNV-1 piezoceramics were obtained by the resonance method for flexural and torsional vibrations of a speci- men fixed on a single-sided support. The dependences were interpreted and their empirical polynomial relationships were derived. A region of constant elasticity and shear moduli was found for TsTSNV-1 piezoceramics in the temperature range of 330-360 K. The electrode-coated layer on the piezoelectric element was found to affect the elasticity moduli of TsTBS-3 and TsTSNV-1. The data obtained may be useful for the development of vibrational and piezoelectric transducers. The problem of operational reliability of piezoelectric transducers for physical magnitudes is directly related to the stability of the characteristics of their sensitive elements. This is especially important for vibra- tional transducers used for monitoring the parameters of power units in zones with elevated temperatures or under radiation. Piezoceramic compositions that have constant piezoelectric, dielectric, and elastic charac- teristics over a sufficiently wide temperature range are used for these piezoelectric transducers. The piezoelectric characteristics of industrial piezoceramic compositions have been studied rather com- prehensively (1, 2). Unlike these characteristics, the temperature dependences of the elasticity and compli- ance moduli have been studied insufficiently (3), though it is impossible to quantitatively estimate the rigid- ity, loading capability, and stressed-deformed state of structure elements if the elastic characteristics of materials in the operating temperature range are unknown. The available data on these dependences were obtained by the traditional "resonance-antiresonance" (R-A) method, which is limited to measurement of constants only for polarized ceramics in a temperature range restricted by the Curie point (2).