基于气体基压电复合材料的线聚焦空耦超声传感器研制与应用

摘要

空气耦合式超声检测技术因具有非接触、无损伤等特点,被广泛应用于材料的非接触检测.本文从晶硅太阳能电池的实际检测需求出发,设计并制作了一种气体基线聚焦空气耦合(空耦)式超声传感器,与传统的聚合物基空气耦合(空耦)式超声传感器相比,气体基线聚焦空耦传感器利用了3D打印技术将聚合物基框架改进为镂空结构,进一步降低了压电复合材料的声阻抗.所研制的传感器中心频率约为150 kHz,聚焦半径为20 mm,孔径为28 mm.对传感器进行了激励接收性能测试,并采用空耦超声 Lamb 波检测技术,对含有裂纹缺陷的单晶硅太阳能电池片进行非接触式检测,通过分析接收信号的幅值信息并利用相关系数法,完成了对裂纹缺陷的检出和定位,实现了气体基线聚焦空耦传感器在缺陷检测中的应用.%Air-coupled ultrasonic testing technology,possessing the characteristics of non-contact and non-destruc-tion,is widely used in nondestructive detection for materials.An air-based line-focus air-coupled ultrasonic trans-ducer was designed and fabricated according to the measurement of crystalline silicon solar cells.Compared to the ul-trasonic transducer based on the traditional polymer matrix,the air-based line-focus air-coupled ultrasonic transducer adopted the 3D printing method to hollow out the polymer matrix frame,which will further reduce the acoustic impedance of piezoelectric composites.The center frequency of the transducer is about 150 kHz,and the focus radi-us is 20 mm,aperture is 28 mm.The generating and receiving performance of the transducer was measured.An crack detection experiment was implemented on a monocrystalline solar cell by air-coupled Lamb waves.The crack can be located by analyzing the amplitude of the received signals,furthermore,a correlation analysis was performed to extract the characteristics of the cracks.