Development of new and high performance piezoelectric smart devices having multifunctionality

为了实现多功能、高性能的压电器件，本研究开发了一种新型铝基复合材料，其中嵌入了带有内电极的压电陶瓷纤维，取得了以下成果。1.采用界面成形/粘接的方法，可以将脆性金属芯压电纤维嵌入到铝基材料中，而不会造成损伤。利用这种方法，中空压电纤维可以用过程中产生的残余合金填充形成其内部电极，并成功地嵌入到铝基中。2.由于该复合材料的极化-电场关系产生了磁滞回线，可见埋入金属芯的压电纤维是作为压电材料工作的。在振动试验和冲击试验中产生的输出电压波形显示了应变和冲击传感的可能性。3.由于铝基复合材料在冲击试验中产生的响应波形优于树脂基复合材料。用中空压电纤维制作的器件与用金属芯压电纤维制作的器件性能相当。4.通过对制作工艺的改进，消除了薄贴式器件中埋入的压电纤维周围的共晶合金残留物和孔洞，使器件的输出电压达到常规器件的6倍。5.利用电子束云纹法对埋入的压电纤维的残余压应力进行了计算，结果表明，埋入的压电纤维承受着大约1 Gpa的很高的压应力，而且这种很高的各向同性残余应力不会干扰高输出电压的产生，因为即使通过热处理去除IF后，残余应力的大小也不会发生变化。

In this research, new aluminum matrix composites embedded with the piezoelectric ceramic fiber which have an internal electrode were developed to realize multifunctional and high performance piezoelectric devices, and the following results were obtained. 1. The brittle metal-core piezoelectric fiber can be embedded in aluminum matrix without damage by the interphase forming/bonding method. Using this method, hollow piezoelectric fiber can be filled with the residual alloy produced during the process to form its internal electrode as well as successful embedment in the aluminum matrix. 2. As the poling - electric field relationship of this composite generates a hysteresis loop, it is clear that the embedded metal-core piezoelectric fiber is working as piezoelectric material. The waveform of the out-put voltage generated in the oscillation test and the impact test shows the possibility of strain and impact sensing. 3. As the responding waveform generated in the impact test of the aluminum matrix composite is superior to that of the resin matrix one. The performance of the device using the hollow piezoelectric fiber is as good as the one using the metal-core piezoelectric fiber. 4. The residuals of eutectic alloy and voids around the embedded piezoelectric fiber produced in the thin and patch type device can be removed by modification of the fabrication process, and the output voltage of this device reaches 6 times of that of the conventional one. 5. The compressive residual stress working on the embedded piezoelectric fiber was evaluated using the electron beam moire method, and it was shown that the piezoelectric fiber is subjected to a very high compressive stress of about 1 Gpa, and was also shown that the very high and isotropic residual stress doesn't disturb generation of the high output voltage because the value did not change even after removal of if by heat treatment.