3D printing of CaBi₄Ti_3.925(Nb_2/3Mn_1/3)_0.075O₁₅ ceramics for high temperature ultrasound transducer

Abstract

Bismuth layer-structured CaBi4Ti3.925(Nb2/3Mn1/3)0.075O15 (CBTNM) piezoelectric ceramics have been prepared using stereolithography (SL) technology. The effects of various solid contents (76–82wt%) of CBTNM ceramics on the slurry viscosity, phase structure, microstructure, and electric performance were studied in detail. At a solid content of 82wt%, the ceramic exhibits good piezoelectric properties. The piezoelectric constant d33, thickness-mode electromechanical coupling coefficient kt, and Curie temperature Tc were 21 pC/N, 47%, and 790 ℃, respectively. The piezoelectric constant of the ceramic has a good stability up to 500 ℃. Furthermore, a high-temperature ultrasound transducer was designed and fabricated based on the CBTNM ceramic, and its pulse-echo performance was characterized from room temperature (RT) to 250 ℃. The pulse-echo performance indicates that the −6 dB bandwidth and echo amplitude of the transducer decrease slightly, but still work normally up to 250 ℃. These results indicate that the transducer fabricated based on CBTNM ceramics has potential in high-temperature testing applications.