为了提高超声电机的环境适应性与能量转换效率, 本文分析并制造了宽温域低损耗的新型压电材料与摩擦功能材料, 提出了通过相结构调控、增加第三组元、引入偶极子缺陷钉扎畴壁等手段制备宽温域低损耗压电陶瓷材料的设计与制造方法; 为了提高超声电机摩擦界面能量传递效率及环境适应性, 设计了具有高摩擦系数、低磨损率且耐高温的聚酰亚胺复合材料。结果表明, 与传统材料相比, 新型压电陶瓷材料具有低介电损耗、高机械品质因数及高温度稳定性的优势, 使超声电机的能量转换效率提高3.3%, 而新型聚酰亚胺基摩擦材料在摩擦系数、耐磨性以及温度范围等指标上均有明显提高, 使电机的最大效率提高了6.19%。综合两种新型材料后, 超声电机的最大效率提升了13.6%, 可靠工作温度从-40~70 ℃提升至-60~120 ℃。本文提出的压电与摩擦功能材料既增强了超声电机的环境适应性, 也改善了电机输出性能, 对超声电机在航空航天等高端装备中的应用具有重要的意义。

In order to improve the environmental adaptability and energy conversion efficiency of ultrasonic motors, a novel piezoelectric and friction material with good temperature stability and low dielectric loss was been prepared and studied systematically in this paper. A new piezoelectric material was proposed based on the results of phase structure modulation, introducing of third end-member, introducing dipole defects to pin domain walls. In order to improve the energy transfer efficiency and environmental adaptability of the friction interface of ultrasonic motor, a novel polyimide composite material with high friction coefficient, low wear rate and high temperature resistance was designed. Finally, in the assembly of the ultrasonic motor, the piezoelectric and friction functional materials proposed in this paper are applied. The results show that the new piezoelectric ceramic materials have the advantages of low dielectric loss, high mechanical quality factor and high temperature stability compared with traditional materials. To be specific, the energy conversion efficiency of the ultrasonic motor increased by 3.3%. The new polyimide friction materials have significantly improved the friction coefficient, wear resistance and temperature range, which increased the maximum efficiency value of the ultrasonic motor by 6.19%. Moreover, after integrating the two new materials, the maximum efficiency value of the ultrasonic motor has increased by 13.6%, and the usage temperature range has increased from -40-70 ℃ to -60-120 ℃.The piezoelectric and friction functional materials proposed enhance the environmental adaptability of the ultrasonic motor and improve the output performance of the motor in this paper, which is of great significance for the application of ultrasonic motors in the equipment for aerospace and other high-end fields.