Sol–gel composite material characteristics caused by different dielectric constant sol–gel phases

Abstract

Ultrasonic transducers prepared by a sol–gel composite method have been investigated in the field of nondestructive testing (NDT). Sol–gel composite materials could be ideal piezoelectric materials for ultrasonic transducer applications in the NDT field, and a new sol–gel composite with desirable characteristics has been developed. Three kinds of sol–gel composite materials composed of different dielectric constant sol–gel phases, Pb(Zr,Ti)O3 (PZT), Bi4Ti3O12 (BiT), and BaTiO3 (BT), and the same piezoelectric powder phase, PbTiO3 (PT), were fabricated and their properties were compared quantitatively. As a result, the PT/BT, sol–gel composite with the highest dielectric constant sol–gel phase showed the highest d 33 and signal strength. In addition, only PT/BT was successfully poled by room-temperature corona poling with reasonable signal strength.

Mn-Doped CaBi4Ti4O15/Pb(Zr,Ti)O3 Ultrasonic Transducers for Continuous Monitoring at Elevated Temperatures

“…Titanium was chosen as the substrate material because of its high-temperature durability and light weight so that its temperature quickly becomes equal to that of the furnace atmosphere. CBT/PZT films were manufactured via a sol-gel spray technique, and the details of the fabrication process can be found in elsewhere [9,10,11,12,13,14,15,16]. First, 0.5 wt % Mn-doped CBT raw material was manufactured by a conventional solid-state reaction method [14].…”

“…Sol-gel composite ultrasonic transducers have been investigated for the industrial NDT applications [9,10,11,12,13,14,15,16]. Sol-gel composites consist of ferroelectric powders and a dielectric sol-gel solution.…”

“…If sol-gel composite films are directly fabricated on the test object, an acoustic couplant is no longer necessary since sol-gel composite films establish high acoustic bonding with the substrates during the fabrication process. Furthermore, it is possible to fabricate sol-gel composite films on targets with complex geometry by using the spray technique [10,11,12,13,14,15,16]. Therefore, sol-gel composite ultrasonic transducers are applicable for industrial ultrasonic NDT at elevated temperatures.…”

Thin, flexible, and biocompatible medical ultrasound array transducer using a sol–gel composite spray technique

“…We have previously developed ultrasonic transducers using the sol-gel composite spraying (SCS) method for nondestructive testing. [17][18][19][20][21][22][23][24] This technique allows the production of flexible, thermally robust sensors with broadband acoustic properties. However, previous studies did not utilize an array structure capable of generating B-mode images, nor were they sufficiently biocompatible for medical applications.…”

Polarity effect of corona discharge poling for sol-gel composite-based ultrasonic transducers

“…1,2) The thick porous films made by solgel composite materials have helped realize ultrasonic transducers with variable center frequency (in the range of 2-50 MHz); such transducers are suitable for non-destructive testing (NDT) applications. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Owing to the porosity of solgel composite films, sol-gel composite-based ultrasonic transducers exhibit high temperature durability, curved surface applicability, reasonable signal strength, and high signalto-noise ratio (SNR), in addition to the suitable frequency range for NDT. 11,20) Therefore, sol-gel composite-based ultrasonic transducers have a good potential for industrial applications.…”