Key Engineering Materials Vols. 291-292

Abstract: The current application of fluids in grinding processes is discussed, the issues related to the use of both mineral oil and water based fluids and the desire to move towards minimum quantity lubrication (MQL) or even dry grinding. The impact of fluid application strategy on workpiece quality is considered. In particular the importance of reliable thermal modelling and knowledge of the thermal partitioning of heat is essential if robust fluid application strategies are to be developed. Examples are given showing how an understanding of the thermal characteristics of the process can be used to develop different and successful fluid application strategies for various grinding regimes from creep feed through to high efficiency deep grinding (HEDG). The possibility of using solid lubricants is also discussed for particular grinding regimes.

Abstract: The paper represents an experimental study of the burr formation mechanism in feed direction. The influence of tool angles and workpiece angles, as well as and other cutting conditions on burr dimensions is considered. The work contains experimental graphs of burr cross-sections obtained using a laser measurement system at various stages of burr formation. The analysis of the experimental work shows that, depending on the cutting conditions, a few mechanisms of burr formation can be distinguished. The study could be useful in the search for optimal tool geometry for burr minimization and for the modeling of a burr formation mechanism.

Abstract: Micro burrs formed in micro parts are not subject to be removed by the conventional deburring method for marco parts. Magnetic abrasive deburring method which was proved to be effective for small burrs are applied for deburring the micro burr in electric gun parts used in TV monitor. A specific magnetic inductor is designed and manufactured for this part. To improve the deburring performance, vibration table is used for increasing the relative velocity. To evaluate the deburring capability and surface finishing, edge shape, surface roughness and composition of surface material are measured precisely. It is verified the chemical composition of surface is not affected by the powder composition when the proper powder are used with coolant.

Abstract: Recently, wet blasting is generally used such as liquid honing and water jet machining in surface before plating of stainless steel. The outstanding feature of wet blasting is to prevent generation of static electric charge, to use micro abrasive grain, and to have cushioning for workpiece. On the other hand, the disadvantage of wet blasting is to generate corrosion of equipment and liquid waste under processing. Moreover, the using abrasive grain is available on a limited basis. In particular, improvement disposal of liquid waste under processing is crucial in the near future. This paper makes proposal for improvement of surface texture by utilizing dry blasting, and it conducts improvement of surface texture about martensite stainless steel (SUS420J2 In JIS), which is used in material for scale applications. As a result, it is cleared that relationship between surface texture and blasting conditions. Furthermore, based on these results, it reports relationship between surface texture and wettability.

Abstract: In order to find a solution to the problem of inefficiency in magnetic abrasive finishing (MAF), electrochemical finishing (ECF) has been introduced to realize compound finishing. A new idea of integrating a magnetic pole with an electrode pole has been proposed as electrochemical magnetic abrasive finishing (ECMAF). At the same time, the occurrence of broken and dropped magnetic abrasives (MAs) has been discussed from the point of view of probability. Research on stock removal and surface roughness shows that the passive film has been removed continuously with a new substrate material emerging during the process of machining, which accelerates the process of electrochemistry to realize the surface finishing. The finishing efficiency and surface quality have been improved by the combination of MAF with the electrochemistry process, and the various cutting behaviors of MA in ECMAF.

Abstract: This paper examines a new magnetic field assisted machining process using a magnetic machining jig. By using this process, a high efficiency and high quality internal finishing process can be achieved, and it was clarified that it was very effective to finish the internal surface of a thick tube (5~30mm in thickness). In this study, the experiments performed on the SUS304 stainless steel tubes (10mm in thickness) examine the applicability of improving the internal surface roughness and the roundness of inside tube, and it also examine the effects of a rotational speed of the magnetic machining jig. The results showed that this processing method enables improve the internal surface roughness and the roundness of inside tube. It is clarified that the roundness of inside tube is highly dependent on the rotational speed of magnetic machining jig, and the roundness can be improved rapidly at a higher rotational speed with the magnetic machining jig.

Abstract: The deficiency in the variety of available magnetic abrasive results in a narrow range of finishing performance. To break through this difficulty, this research developed iron-based gas-atomized magnetic tools. The magnetic tool has a spherical shape and micro-crevices on the surface. The micro-crevices perform the role of cutting instead of the edges of the existing magnetic abrasive, thereby achieving abrasive-less finishing. This paper studies the finishing performance of the developed magnetic tool. Compared to the existing magnetic abrasive, this magnetic tool shows more efficient finishing performance in the internal finishing of SUS304 stainless steel tubes used for sanitary piping systems.

Abstract: This paper analyzes the effectiveness of using Magnetic Abrasive Finishing (MAF) to remove burrs on drilled holes located on planes. Basic elements of the equipment in this method are a magnetic inductor; powder with magnetic and abrasive properties, which serves as the cutting tool; and the face electromagnetic inductor and the vibrating table, which were developed for deburring and finishing on flat surfaces. The performance of magnetic abrasive powders produced by industry is also evaluated. A new technique was developed to compare the performance of the magnetic abrasive powders and to find the powder that is appropriate for finishing and deburring drilled holes placed on a plane steel surface.

Abstract: In this paper, the new technique involving comparison and optimization of conditions for Magnetic Abrasive Finishing (MAF) is suggested, taking into account the basic laws stated for process MAF. The formulas for the calculation of the criteria for optimization are created when the process MAF is used for polishing, removal of burrs, and other purposes. The application of the technique is shown in an experiment on the optimization conditions for the removal of burrs after drilling using the MAF method. The technique can be used after standards for this process are developed.