Study of Next Cavitation Shotless Peening

主要研究结果如下：1.对空气中的空化射流进行了观察，发现高速水射流周围周期性的空化脱云和低速水射流的脉动相互干扰。2.对纯铝试件进行了空化无喷射喷丸处理。再结晶-刻蚀实验表明，该合金的塑性变形是由空化无喷射喷丸引起的。3.用空化冲击计数器测量了空化冲击能。结果表明，空化射流在空气中产生的空化冲击比在水中产生的空化冲击更强烈。4.根据塑性变形坑的形状估计空化冲击的应力分布。为了将空化喷丸技术应用于摩擦学领域，揭示了钛合金中残余压应力的引入。5.为了建立空化喷丸的监测方法，揭示了PVDF传感器测量的冲击能量与激光多普勒测速仪测量的振动之间的关系。6.对所提出的空化喷丸与传统喷丸方法进行了比较。从压缩残留量的引入和疲劳强度的提高两方面揭示了喷丸方法的不同。7.为了控制空化冲击强度，对空化无喷丸喷丸产生的塑性变形坑进行了精确测量。利用低速水射流的喷射压力和喷距成功地控制了空化冲击的压力分布。8.优化了低速水射流喷射压力和喷距这两个空化喷丸的主要参数。

The main results obtained are as follows :1.The cavitating jet in air was observed and it was revealed that the periodical cavitation-cloud-shedding around the high-speed water jet and the fluctuation of the low-speed water jet were interfered each other.2.Pure aluminum specimen was treated by the cavitation shotless peening. It was revealed by means of recrystallization-etch technique that the plastic deformation was induced by the cavitation shotless peening.3.The cavitation impacts energy was measured by the cavitation impact counter. It was revealed that the cavitation impacts induced by the cavitating jet in air were more intense compared with that of the cavitating jet in water.4.The stress distribution of cavitation impacts was estimated by the shape of plastic deformation pits. In order to apply the cavitation shotless peening to tribology area, the introduction of compressive residual stress into titanium alloy was revealed.5.In order to establish monitoring method of cavitation shotless peening, the relation between the impact energy measured by the PVDF sensor and the vibration measured by the laser doppler velocity meter were revealed.6.The proposed shotless peening and the conventional shot peening were compared. The difference of the peening methods in view point of introduction of compressive residual and the improvement of fatigue strength was revealed.7.In order to control the cavitation impact intensity, the plastic deformation pits produced by cavitation shotless peening were measured precisely. The pressure distribution of cavitation impact was successfully controlled by the injection pressure of the low-speed water jet and the standoff distance.8.The injection pressure of the low-speed water jet and the standoff distance, which were the main parameters of the cavitation shotless peening, were optimized.