利用放电等离子烧结高致密度的铌酸钾钠基无铅压电作为陶瓷相,通过改进后的切割-浇注法复合基体相环氧树脂,制备得到陶瓷柱宽40μm、间隙40μm、纵横比〉5的超微细化结构的1-3型铌酸钾钠基陶瓷/环氧树脂无铅压电复合材料(1-3 connective lead-free piezoelectric composites,1-3CLFPC)。1-3CLFPC薄膜的电学性能显示出其作为超声换能器工作的优势:压电电压常数g33达到247×10-3 m2/C,厚度机电耦合系数kt为40.7%。超微细化结构设计也使得1-3CLFPC薄膜的工作频率提高到5 MHz以上,可满足高频医疗超声诊断领域的需求。
Choosing highly dense potassium sodium niobate-based lead-free piezoelectric ceramics made by the spark plasma sinter-ing method as ceramic phase,micro-scale 1-3 connective lead-free piezoelectric composite(1-3CLFPC) thick films were fabricated through a modified dice-fill method,with ceramic pillar width of 40 μm,pillar spacing 40 μm and aspect ratio 5.These 1-3CLFPC thick films show their advantages in transducers: piezoelectric voltage constant g33 of 247 × 10-3 m2/C and thickness-mode electrome-chanical coupling coefficient of 40.7%.Furthermore,the micro-scale structure fulfilled working frequency of these 1-3CLFPC thick films above 5 MHz,satisfying the need for high-frequency medical ultrasound imaging.