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

Bismuth layer-structured CaBi4Ti3.925(Nb2/3Mn1/3)(0.075)O-15 (CBTNM) piezoelectric ceramics have been prepared using stereolithography (SL) technology. The effects of various solid contents (76-82 wt%) of CBTNM ceramics on the slurry viscosity, phase structure, microstructure, and electric performance were studied in detail. At a solid content of 82 wt%, the ceramic exhibits good piezoelectric properties. The piezoelectric constant d(33), thickness-mode electromechanical coupling coefficient k(t), and Curie temperature Tc were 21 pC/N, 47%, and 790 degrees C, respectively. The piezoelectric constant of the ceramic has a good stability up to 500 degrees C. 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 to 250 degrees C. 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 degrees C. These results indicate that the transducer fabricated based on CBTNM ceramics has potential in high-temperature testing applications.