학술논문
Lead-free piezoelectric materials and composites for high frequency medical ultrasound transducer applications
Document Type
Conference
Author
Source
2014 IEEE International Ultrasonics Symposium Ultrasonics Symposium (IUS), 2014 IEEE International. :903-906 Sep, 2014
Subject
Language
ISSN
1051-0117
Abstract
Lead-free ceramics based on the (1−x)Ba(Zr 0.2 Ti 0.8 )O 3−x (Ba 0.7 Ca 0.3 )TiO 3 (BZT-BCT) system have been reported to exhibit piezoelectric properties comparable to lead zirconate titanate ceramics, and are thus being considered as replacement materials for some applications. In this work, the possibility of fabricating BZT-BCT based 1–3 piezocomposites for high frequency ultrasound imaging has been explored. An investigation of the interdependence of synthesis, processing and sintering conditions on the physical, structural, microstructural and functional properties of piezoelectric compositions in the BZT-BCT system has been carried out. Ceramic powders with a composition of 0.5BZT-0.5BCT and a particle size of 1 µm were chosen for the fabrication of the ceramic segments which were subsequently sintered at 1425°C. A novel randomised pattern that has recently demonstrated its advantages in suppressing undesirable spurious resonances was adopted for the lead-free composites and a micro-moulding technique based on gel casting ceramic processing has been used for the fabrication of the composites. A 0.5BZT-0.5BCT based randomised composite operating at ∼30 MHz with an electromechanical coupling factor of 0.63 has been achieved.