DEVELOPMENT OF POWDER JET PROCESSING METHOD AND A MECHANISM CHANGE IN PROCESSES OF MATERIAL REMOVAL AND POWDER DEPOSITION

亚毫米级（0.01- 1 mm）的微传感器和微致动器的发展受到了极大的关注，这对于诸如微机械的微电子/机械系统（MEMS）是必需的。在本研究中，我们开发了一种粉末喷射工艺，这是磨料喷射加工的应用之一。在此过程中，微粒子（φ 0.1-几μm），这是由载气加速，以高速撞击，并在真空或大气条件下积累到基板上，并形成厚膜。虽然沉积速率大到足以制造亚毫米尺寸的功能结构，但是存在与结构的形状精度和密度相关的沉积速率和混合比不稳定的问题。这是因为载气和微粒的混合和喷射机制不充分。去年，我们开发了粉末喷射装置，可以定量喷射微粒， 关于我们 在真空条件下间歇性放电，并进行了实验。然而，由于真空条件下存在各种限制，考虑到实际应用，大气条件下的粉末沉积比真空条件下更有用。因此，确认了在大气条件下粉末沉积的可能性。接下来，我们研究了颗粒的过渡直径，在该过渡直径处，机制从材料去除变为沉积。此外，还研究了喷砂速度、喷砂压力、粉末材料和工件材料等喷砂条件对厚膜结合强度的影响。实验结果表明，在大气压下将氧化铝或碳化硅颗粒喷到玻璃或硅基片上时，颗粒的过渡直径约为2.0μm，较小的颗粒表现出粘附现象。沉积高度在几秒钟后趋于稳定，厚度达到20-120μm。并且很明显，喷砂颗粒的动能和基底工件的硬度对粘合剂特性有很大的影响。此外，我们提出了一种新的评价方法的机械性能的薄膜的显微硬度和动态硬度值的差异。在该方法中，在硅衬底上形成的膜的硬度大于在玻璃上形成的膜的硬度。此外，证实了电子工业材料，如PZT或铁氧体，可以在常压下沉积。少

Much attention has been paid to a development of micro-sensors and micro-actuators on the order of sub-millimeter size (around 0.01-1mm), which are necessary for micro electrical/mechanical system (MEMS) such as a micro-machine. In this study, we developed a powder jet process, which is one of applications of abrasive jet machining. In this process, micro-particles ( φ 0.1-several μm), which are accelerated by a carrier gas, impinge with a high velocity and accumulate onto a substrate under vacuum or atmospheric condition, and forms thick film. Though the deposition rate is large enough to manufacture a functional structure of sub-millimeter size, there are problems that the deposition rate and mixture ratio, which are related to form accuracy and a density of the structure, are unstable. This is because a mixing and blasting mechanism of carrier gas and micro-particle is inadequate. Last year, we have developed the powder jet device that can blast micro-particles quantitatively and in … More termittently under vacuum condition, and experimented with the device. However, because there are various limitations under vacuum condition, taking practical use into consideration, powder deposition under atmospheric condition is more useful than under vacuum condition. Thus, a possibility of a powder deposition under atmospheric condition was confirmed. Next, we investigated a transition diameter of a particle, at which the mechanism changes from a material removal to a deposition. Furthermore, influences of blasting conditions such as blasting velocity and pressure, and matrials of powers and workpiece material on adhesive strength of formed thick film were investigated. The results of the experiments show that the transition diameter of particle is about 2.0μm and a smaller particle shows an adhesion phenomena when blasting alumina or silicon carbide particles to glass or silicon substrate under atmospheric pressure. And deposition height became stationary after several seconds and reached 20-120μm in thickness. And it becomes clear that kinetic energy of blasted particles and hardness of a substrate workpiece have a large influence on adhesive characteristics. In addition, we suggest a new evaluation method of mechanical properties of the film from a difference of micro-hardness and dynamic hardness values. In this method, the hardness of the formed film on a silicon substrate is bigger than on a glass. Furthermore, it is confirmed that electronic industry materials, such as PZT or ferrite, can be deposited under atmospheric pressure. Less