Temperature dependence of the fatigue and mechanical properties of lead zirconate titanate piezoelectric ceramics

✍ Scribed by Mitsuhiro Okayasu; Masashi Otake; Teruo Bitoh; Mamoru Mizuno

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 839 KB
• Volume: 31
• Category: Article
• ISSN: 0142-1123
• DOI: 10.1016/j.ijfatigue.2009.01.008

✦ Synopsis

This paper presents research results on the temperature dependence of the fatigue and mechanical properties of piezoelectric ceramics. The material being examined is a lead zirconate titanate piezoelectric ceramic, PZT. The fatigue strength apparently increases with increasing sample temperature. The mean endurance limit at 10 5 cycles for the sample tested at 573 K is twice as high as that at 293 K. Similarly, the bending strength of the PZT increases with increasing sample temperature. A maximum bending strength is obtained at a sample temperature between 573 K and 773 K. The increment in the bending strength is attributed to the distorted lattice structure, in which a tetragonal lattice system is being changed to a cubic structure at 573 K, the Curie temperature. On the other hand, the reduction in the bending strength at temperatures greater than 773 K is caused by a reduction in the concentration of oxygen defects and high thermal energy, leading to dislocation movement. A wavy fracture surface with a mixture of transgranular and intergranular fractures is obtained in the samples fractured at temperatures between 573 K and 773 K due to the distorted lattice structure. In contrast, a flat face with transgranular fracture appears in tests at the room temperature and the high temperature (over 773 K). Details of the fracture mechanism are further discussed.