Papers by Keyword: Micro Precision Machining

Abstract: This paper describes machining characteristics of high spindle speed WEDG using the electrostatic induction feeding method. In this method, non-contact electric feeding allows the workpiece rod to be rotated at a high speed of up to 50000rpm. Since the temperature rise on the workpiece surface is low, the material removal rate was two times higher and the surface roughness was also improved compared to the normal RC discharge circuit where the rotational speed was 1000rpm at the highest due to contact electric feeding using a brush. Furthermore, micro rods thus prepared were used as tool electrodes to machine micro-holes with the same rotation speed of 50000rpm. It was found that smaller gaps and better straightness can be obtained due to the high flushing efficiency at the high spindle speed.

Abstract: The finishing process of a metal mold depends on the hand work of experts by using a whetstone tool in many cases. This is because it is difficult to treat the three-dimensional configuration, such as free-form surfaces and convex and concave configurations. To overcome this difficulty, we propose a dynamic magnetic field assisted finishing using magnetic compound fluid (MCF) for three-dimensional configurations. In this paper, we demonstrate the MCF slurry (MCF mixed abrasive and cellulose fiber in) under dynamic magnetic field shows the high form restoration and generates the high normal force compared to that under static magnetic field; resulting in shows the high finishing performance. Moreover, we compare and discuss the surface roughness and form accuracy under both static and dynamic magnetic fields against three-dimensional configuration made of high hardness non-ferrous mold steel HPM75, which is used for plastic injection mold.

Abstract: The copying characteristic of the tool motion on the workpiece profiles is investigated. Assuming that the workpiece profile consists of sinusoidal-wave components, the amplitude ratio between the workpiece profile and the tool motion is defined as copying rate . An experiment was conducted to identify in shaping of electroless plated nickel. With polycrystalline diamond tools, the copying rate was obtained as =1.16. The result indicates that the amplitude of the workpiece profile can be larger than that of the tool motion. Shaping of slot profiles was carried out to investigate the influences of depth of cut, rake angle and relief angle on the copying characteristic. The depth of slot was larger than the tool displacement in the Z-direction by 0.1-0.4 μm when the rake angle was -5 degrees and the relief angle was 12 degrees.

Abstract: Powder blasting is similar to sand blasting and effectively removes hard and brittle materials. With an increase in the need for machining of ceramics, semiconductors, electronic devices and LCDs, micro abrasive jet machining has become a useful technique for micro-machining. In this study, we first investigated the effects of the blasted glass surface’s characteristics and shape under different blasting parameters; second, we examined the predictive models for material removal and surface roughness that have been developed in terms of blasting pressure, scanning speed and abrasive flow, using response surface methodology by experimental data. The established equation shows that the blasting pressure was the main factor influencing the material removal and surface roughness. In addition, analysis of variance for the firstorder model of material removal and surface roughness shows that the coefficient of determination (R2) is 99% and 98%, respectively. The associated p-value for the two models was lower than 0.01, indicating that the models are statistically significant.