连接界面结合强度低和气泡缺陷是限制激光连接高分子材料与陶瓷接头强度提高的两个关键因素，本项目以PMMA与Si3N4为研究对象，首次提出将超声辅助激光连接技术应用于这两类材料的连接。利用超声波振动增强界面处机械结合、物理结合和化学键合作用，达到提高界面结合强度的目的。用SEM、XPS、化学键合热力学、润湿热力学和动力学等手段明晰接头界面结合机理和超声对界面结合的增强原理，并对此方法中所涉及到的物理现象及超声作用规律进行研究。在声压和温度场数值计算的基础上，通过设计超声工具头表面结构和工艺参数调控声压和温度分布，使气泡平移至低压高温区域并从焊缝边界逸出，实现消除气泡的目的。通过分析超声波和激光耦合作用对气泡在水平方向移动轨迹的影响规律，并结合高速摄影仪观测结果揭示气泡消除机制。通过该项目的研究，可以有效解决高分子材料与陶瓷异质结构激光连接界面结合弱和气泡缺陷的问题，具有重要的科学和应用价值。

The weak bonding interface and bubble defects are two key factors affecting dissimilar joint strength in laser joining polymer materials to ceramic. In this project, we propose a new method called ultrasound aided laser joining of medical polymer materials to bioceramics, in which PMMA and Si3N4 are the material to be joint. Utilizing ultrasonic vibration to promote the mechanical bonding, physical bonding and chemical bonding at the joint interface; as a result a strong bonding interface is achieved. This project is going to reveal the bonding mechanism and enhancement principle of the bonding interface by means of SEM, XPS, chemical bonding thermodynamics, wetting thermodynamics and kinetics, the physical phenomena involved in this method and the principle of ultrasonic action are also studied. The combined effects of ultrasonic vibration and laser on the bubble dynamics process and its movement path are analyzed based on the numerical calculation of sound pressure and temperature fields. With a proper ultrasonic tool design and joining parameters to control the sound pressure and temperature fields in the joint specimen, bubbles in the molten plastic pool can be made to move to the low pressure and high temperature region, as a result escape from the edge of joint zone. The bubble removal mechanism will be revealed by the high-speed camera observations and analyzing the effect of ultrasonic and laser coupling on the track of bubble moving in horizontal direction. At last, through the research of this project, it is expected to obtain a new welding technology that can join medical polymer materials to bioceramics with high strength, which brings important scientific and practical significance.