Papers by Author: Kimiyuki Mitsui

Abstract: The application of powder mixed dielectric to improve the efficiency of electrical discharge machining (EDM) has been acknowledged extensively. However, the study of micro-size powder suspension in micro-EDM field is still limited. In this research, nano and micro size powder of MoS2 were used as catalyst agent. Powder suspension in different size was able to provide significant improvement in material removal rate and surface quality to increase the efficiency in μ- EDM processes.

Abstract: The optical measuring device developed in this study is based on laser autocollimation and can measure the radial error motions of a miniature ultra-high-speed spindle having a maximum rotational speed of 200 krpm. The maximum response frequency of this optical measuring device is over 500 kHz, while the frequency of the radial error motion at 200 krpm is 3.33 kHz for 1 undulation per revolution (upr), and 333 kHz for 100 upr. In addition, the optical measuring device is capable of a highly detailed analysis of the radial error motion of a miniature ultra-high-speed spindle since it has a high signal-to-noise ratio due to little susceptibility to electrical noises.

Abstract: The mechanism of fracture in micro-electrical discharge machining (-EDM) processes is related to the discharge pulses energy. This paper investigates the correlation of fractures and discharge pulses energy in the -EDM of polycrystalline diamond (PCD) to the acoustic emission (AE) signals. The evaluation of fracture mechanism was done by measuring the generation and propagation of elastic wave in single discharge pulse by using AE sensor. The results show a strong correlation between fractures and discharge pulses energy to the AE signals and mechanism of material removal in the -EDM processes.

Abstract: Cutting tool wear is a major problem in machining processes. It has a great effect on the quality of a workpiece. Thus, monitoring cutting tool wear is very important in order to maintain the workpiece quality as well to reduce production rate and production time. The use of a single sensor in a monitoring system may not be accurate to detect cutting tool wear. In this paper, sensor fusion technology is introduced for monitoring cutting tool wear.

Abstract: In industry, disk type products with a highly accurate surface such as silicon wafer and hard disk, are important elements. To measure these surfaces, an interferometer is used. However, this method generally needs a highly accurate reference surface. Another method to obtain the disk surface profile is by a scanning displacement sensor. However, the output of this sensor is influenced by the parasitic motions of the scanning along the reference guide. This article presents novel measurement procedures, a reversal method, an improved reversal method and a multi-prove method, to measure the circular profile on a disk without any references but with high accuracy.