MICRO-MACHINING OF CERAMICS USING ABRASIVE-JET TECHNOLOGY

本项目涉及微磨料射流加工的基本特征和应用。研制了用于陶瓷微细加工的微ajm装置。它的优点是载气压力比普通装置高3-4倍，并且磨料与载气混合均匀。首先，用激光多普勒测速仪测量了在气流加速作用下磨粒的速度。很明显，磨料颗粒被加速到100到200米/秒之间，大约是声速的60%。其次，提出了一种冲击磨料在工件上分布的测量方法。采用片式激光光源和CCD摄像单元。该方法的原理是基于衍射光强法，并应用图像处理技术得到光强分布。很明显，磨料分布在比喷嘴横截面更大的区域。速度和磨料分布的信息对于选择最优的AJM条件和设计喷嘴形状是有帮助的。对陶瓷（AlN、SiC、Si_3N_4、玻碳、ZiO_2和玻璃）进行了加工试验，揭示了加工特性。此外，对于微ajm应用，还尝试了微钻孔、图案加工和过程中修整。微ajm技术在脆性材料的微加工中表现出优异的性能。

This project deals with the fundamental characteristics and applications of a micro-abrasive jet machining (micro-AJM). The micro-AJM device, which is for micro-machining of ceramics, was developed. It has advantages that the pressure of carrier gas is 3-4 times higher than that of a normal device, and that the mixing of abrasives and carrier gas is uniform.First, the velocity of abrasive particles, which are accelerated with a gas stream, was measured with laser Doppler velocimeter. It is clear that the abrasive particles were accelerated to a velocity of between 100 and 200 m/s, which is approximately 60% of sound speed. Second, a distribution measuring method of attacking abrasive onto the workpiece was developed. Sheet laser light source and CCD camera unit were used. The principle of this method is based on the diffraction light intensity method and image processing technique is applied to get the distribution. It was clear that the abrasives were spread over larger area than the cross section of the nozzle. Information of the velocity and the abrasive distribution is useful in selecting the optimal AJM conditions and in the designing the nozzle shape.Machining tests of ceramics (AlN,SiC,Si_3N_4, glassy carbon, ZiO_2 and glass) were performed and the machining characteristics were revealed. Furthermore, for micro-AJM applications, micro-drilling, pattern machining, and in-process dressing were tried. Micro-AJM technology demonstrated the excellent performance in the micro-machining of brittle materials.