DEVELOPMENT AND EVALUATION OF PRECISION ABRASIVE JET MACHINING DEVICE

点击翻译按钮获取中文摘要

A new device of abrasive jet machining (MM) has been developed for precise etching and patterning of hard and brittle materials such as ceramics, glass and silicon. AJM process is similar to the sand blasting, and effectively removes hard and brittle materials. AIM uses fine abrasive powders and small nozzles whose inner diameter (ID) is below 1mm. As the abrasive jet stream from the nozzle is focused onto the workpiece, small holes or slots can be machined easily. As a conventional AIM device, however, can not control the amount of injecting abrasives precisely, it is difficult to apply to a precision machining. In machining small holes, furthermore, impacting abrasives are accumulated at the bottom of the hole, and prevent the direct impact onto the workpiece. As a result, machining efficiency decreases with the progress of machining. To solve these problems, we developed a new AIM device which is capable of intermittent injection of abrasives. Abrasive grains are supplied intermittently by the cycle of 10 ms using high speed solenoid valves, mixed with continuous stream of high pressure carrier gas, and finally blasted from the nozzle. The device can blast a small amount of abrasives (about 0.5 mg/one cycle). Grain density in the jet stream from the nozzle can be controlled by changing signal frequency for the solenoid valves, When the valve is off, there is no abrasives in the jet stream and the accumulated abrasives are blown off. In this report, machining characteristics of the new AJM device are investigated, and direct etching and patterning of glass without mask are demonstrated.