Microstructural engineering of piezoelectric composites

压电复合材料的微结构工程

• 批准号: EP/V011332/1
• 负责人: James Roscow
• 金额: $ 32.66万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FV011332%2F1
• 关键词: Microstructural; engineering; piezoelectric; composites

This project will create novel fabrication approaches, using the freeze-casting method combined with slip- and tape-casting, to produce piezoelectric composites with microstructures tailored to yield piezoelectric properties that exceed the performance of off-the-shelf materials, whilst providing advantages over traditional manufacturing methods. The global market for piezoelectric ceramics was valued at $19.6 billion in 2019 and is expected to grow in the areas of energy harvesting, IoT-related sensors and piezoelectric composites in the next decade. Piezoelectric composites are critical to the UK's defence (SONAR), and public health (medical ultrasound) sectors, as well as being used widely in the transport and energy industries. Developing new methods for producing high performance piezoelectric composites represents a significant benefit in terms of materials cost and manufacture, as well as device performance, by enabling low-cost fabrication of bespoke piezoelectric materials with properties tuned depending on the desired application.Freeze casting is an effective method for controlling the microstructures of porous materials, whereby pores are templated on solvent crystals whose growth and morphology depends on temperature gradients and freezing behaviour during processing. These porous microstructures, e.g. porous piezoelectric ceramics, can then be infiltrated with polymer second phases to improve mechanical and electrical properties. The properties of piezoelectric composites depend strongly on local interactions between electric- and mechanical fields and the material structure over a range of length scales, from ferroelectric domains (sub-micron) through to macro-structure (on the order of millimetres) of the composites. In this project, the aim is to increase the understanding of these electromechanical field/material interactions in piezoelectric composites and design microstructures to exploit beneficial effects accordingly. This will be underpinned by developing advanced numerical models to both aid with microstructural/fabrication process design, and provide insight into experimental observations of the properties of materials fabricated during the project. The methods that will be investigated offer several advantages over current techniques used to produce commerically available piezoelectric composites. Firstly, the materials can be produced at near-net shape, reducing post-machining processes or manual fibre lay up common for macro-fibre composites fabricated by dice-/arrange-and-fill processes. Secondly, the level of control that is theoretically possible, although not yet realised, by utilising freezing processes to template microstructures, provides the potential to fabricate materials with bespoke properties tuned to specific applications, yielding an optimised combination of piezoelectric, dielectric and mechanical properties to promote enhanced electromechanical coupling between the active piezoelectric and the wider device. Thirdly, the reduced length scale of microstructural features introduced using freeze casting, compared to dice-and-fill composites for example, may provide a route to engineering the inherent properties of the piezoelectric ceramic matrix. Using water as a freezing agent means these processes have a low environmental impact, and near-net shape, optimised composite microstructures with comparable performance to dense piezoceramics will reduce the volume of raw material required in the first place.

该项目将创造新的制造方法，使用冷冻铸造方法结合粉浆和流延，生产具有定制微结构的压电复合材料，以产生超过现成材料性能的压电性能，同时提供优于传统制造方法的优势。2019年，全球压电陶瓷市场价值196亿美元，预计未来十年将在能源收集、物联网相关传感器和压电复合材料领域增长。压电复合材料对英国的国防（声纳）和公共卫生（医疗超声）部门至关重要，并广泛用于运输和能源行业。开发用于生产高性能压电复合材料的新方法在材料成本和制造以及器件性能方面具有显著的益处，通过使定制压电材料的低成本制造成为可能，所述定制压电材料具有根据期望的应用而调整的特性。冷冻铸造是控制多孔材料的微观结构的有效方法，由此在溶剂晶体上模板化孔，所述溶剂晶体的生长和形态取决于加工过程中的温度梯度和冷冻行为。这些多孔微结构，例如多孔压电陶瓷，然后可以用聚合物第二相渗透以改善机械和电气性能。压电复合材料的性能强烈地依赖于电场和机械场之间的局部相互作用以及从复合材料的铁电畴（亚微米）到宏观结构（毫米量级）的一系列长度尺度上的材料结构。在这个项目中，目的是增加对压电复合材料中这些机电场/材料相互作用的理解，并设计相应的微结构以利用有益的效果。这将通过开发先进的数值模型来支持，以帮助微结构/制造工艺设计，并提供对项目期间制造的材料特性的实验观察的见解。将被调查的方法提供了几个优势，目前的技术用于生产可替代的压电复合材料。首先，材料可以以近净形状生产，减少了后加工工艺或手工纤维铺叠，这对于通过切割/切割和填充工艺制造的粗纤维复合材料是常见的。其次，通过利用冷冻工艺来模板化微结构，理论上可能的控制水平（尽管尚未实现）提供了制造具有针对特定应用调整的定制特性的材料的潜力，从而产生压电、介电和机械特性的优化组合，以促进有源压电和更宽的器件之间的增强的机电耦合。第三，与例如切割和填充复合材料相比，使用冷冻铸造引入的微结构特征的减小的长度尺度可以提供一种设计压电陶瓷基质的固有性质的途径。使用水作为冷冻剂意味着这些工艺对环境的影响很小，并且接近净形，优化的复合材料微观结构具有与致密压电陶瓷相当的性能，这将首先减少所需的原材料体积。

项目成果

The unusual case of plastic deformation and high dislocation densities with the cold sintering of the piezoelectric ceramic K0.5Na0.5NbO3

压电陶瓷 K0.5Na0.5NbO3 冷烧结时出现塑性变形和高位错密度的异常情况

• 发表时间: 2023
• 期刊: Journal of the European Ceramic Society
• 影响因子: 5.7
• 作者: Nakagawa N

Improving piezoelectric energy harvesting performance through mechanical stiffness matching

• DOI: 10.1080/15376494.2023.2295383
• 发表时间: 2023-12-14
• 期刊: MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
• 影响因子: 2.8
• 作者: Kurt，Polat;Narayan，Bastola;Orhan，Sadettin
• 通讯作者: Orhan，Sadettin

Energy Harvesting from Water Flow by Using Piezoelectric Materials

• DOI: 10.1002/aesr.202300235
• 发表时间: 2024-01
• 期刊: Advanced Energy and Sustainability Research
• 作者: Zihe Li;J. Roscow;H. Khanbareh;Geoffrey Haswell;Chris Bowen

A comprehensive energy flow model for piezoelectric energy harvesters: understanding the relationships between material properties and power output

• DOI: 10.1016/j.mtener.2023.101396
• 发表时间: 2023-08
• 期刊: Materials Today Energy
• 影响因子: 9.3
• 作者: Zihe Li;J. Roscow;H. Khanbareh;John Taylor;Geoffrey Haswell;C. Bowen