Investigation in to novel piezoelectric materials and manufacturing methods for sonar transducers

总体目标是利用新的压电材料和制造方法在宽频带上增强高功率声纳。超声换能器通常包括有源压电材料和一些辅助无源材料，以控制振动模式，并提供与后表面的负载和阻尼的声学匹配。为了解决声纳换能器设计中的有源部件，单晶PMN-28 PT的纹理版本是通过机械地对准杂乱的晶畴而不是通过自然晶体生长（这是昂贵得多的工艺）对准它们来实现改进的性能的关键。这给出了PMN-28 PT的纹理形式的“k33”和“k31”模式耦合、相对功率密度和相对单位体积成本的一小部分（当与等效单晶材料相比时）。实验室工艺的可重复缩放尚未实现，但将众所周知的商业流延工艺与模板晶粒生长（TGG）相结合，能够以单晶成本的一小部分生产高性能平板和圆柱形。纹理材料有望成为正在展开的压电陶瓷技术革命的重要组成部分。将使用激光烧结和3D打印等现代快速成型技术中常见的增材制造技术来探索设计中无源元件的问题空间。这将允许无源元件设计远离在减材制造中常见的圆柱或直线形态，并允许更深奥的设计策略

The overall objectives are aimed at using new piezoelectric materials and fabrication methods to enhance high power sonar over a wide frequency band.Ultrasonic transducers typically comprise active piezoelectric materials couples with a number of ancillary passive materials to control the mode of vibration and provide acoustic matching to the load and damping at the rear face.The project is two-fold; in order to address the active component within a sonar transducer design textured versions of the Single-Crystal PMN-28PT are key to achieving improved properties by mechanically aligning the jumbled crystal domains rather than align them through natural crystal growth which is far more expensive process. This gives 'k33' and 'k31' mode couplings for the Textured form of PMN-28PT, relative power density and relative at a fraction of the cost per volume when compared to the equivalent Single-crystal material. Repeatable scaling of laboratory process is yet to be achieved, but combining the well-known commercial tape casting process with templated grain growth (TGG) enables the production of high-performance flat plates and cylindrical shapes at a fraction of the cost of a single crystal. Textured material promises to be a significant part of the unfolding piezoelectric ceramic technology revolution.The problem space for the passive components of the design will be explored using additive manufacturing technique that are common in contemporary rapid prototyping techniques such as laser sintering and 3D printing. This will allow passive component designs to move away from cylindrical or rectilinear morphologies that are common in subtractive manufacturing and allow for more esoteric design strategy