Research On Key Technologies Of Piezoelectric Liquid Shock Wave Generator System

It is one of the preference directions of advanced manufacturing technology to explore a high efficient metal processing technology. On the basis of the high energy beam processing, the liquid shock wave processing technology was presented for the first time according to the focus of pulsed ultrasound technology, and it utilizes the high-energy transient pressure wave to process the material lying in the focal area. Integrating the ultrasound technology, advanced manufacturing technology and the material science, the technology, which has many merits such as the energy controllable, low cost, and security, will provide a new method for material processing and have some potential use in the mechanical manufacture area.The piezoelectric shock wave generator system was studied from the aspects of the piezoelectric shock wave generator, the excitation power supply and the measuring system. The experiment system was established to explore the application of the shock wave in nanoparticles dispersion and the preparing technology for the nanocomposites. Details are as follows:1. It was the piezoelectric shock wave generator basing on the focus of pulsed ultrasound that plays a very important role in the system. The lens style element shock wave generator was systematically studied in the way of acoustic pressure distribution and focal plane. A multi-element shock wave generator, consisted of many lens style element shock wave generators in a spherical shell, was designed. The acoustic focal point of the multi-element shock wave generator was overlaped with the spherical center of the shell. The acoustic field of the multi-element was calculated by the coordinate transform method and simulated by MATLAB. Effects of the designed parameters including frequency, element size and number of elements on the acoustic pressure and the focal capability were investigated, on the basis of it, theoretical foundation of the design of multi-element shock wave generator was supplied.2. By investigating the matching layer thickness theory and the influence of the thickness of the matching layer on the shock wave generator, the single-element and the multi-element shock wave generator was designed and its technical process was constructed, which assured the good performance of the shock wave generator. The piezoelectric analysis was made to the high frequency lens style shock wave generator with ANSYS, which provides a theoretic basis for the design of the excitation power supply and the choice of the excitation frequency.3. The energy transition process was approached, besides, the input power and the output power of the excitation power supply were measured by the Universal Power Analysis and the results show that the excitation power supply works realiably. Integrating the conical reflecting target and the absorbing targe, the testing device of the radiation force was designed, which provides a means to analyze the performance of the shock wave generator. The acoustic field in the focal point was measured by the pressure sensor, which played an important part in the special transfer process of the liquid shock wave.4. A new nanoparticles dispersion method was presented, which applied the liquid shock wave to disperse the nano-SiO2 nanoparticles, nano-MMT and CNTs in different liquid phase. The dispersion effect was detected by UV-Vis spectrophotometry, XRD and TEM and the results showed that it has high dispersion efficiency and good dispersion effect. Furthermore nano-SiO2 in epoxy was dispersed by the liquid shock wave method and the SiO2/epoxy nanocomposites was prepared. The performance of the nanocomposites was analyzed by the Barcol hardness meter, measuring microscope and infrared spectrometer, which laid the foundation for the application of the liquid shock wave.