• Journal of the Korean Society for Precision Engineering
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• v.30 no.12
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• pp.1245-1251
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• 2013

This study has focused on development of ELID monitoring system and its application to ELID grinding of structural ceramics. ELID monitoring system was consisted of grinding equipment, ELID power supply, grinding wheel, electrode and monitoring program. It can give a real time data to check spindle grinding resistance, wheel revolution, dressing current and voltage in ELID grinding process. The performance of developed system was evaluated by applying to grinding of structural ceramics, silicon carbide and alumina. As the results of experiments, monitored data for spindle resistance and ELID dressing current was useful to check steady-state ELID grinding process. From the comparison of spindle resistance between ELID grinding and conventional grinding process according to change of depth of cut, it could be confirmed that the spindle resistance in ELID grinding was lower than conventional grinding process.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.167-173
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• 1999

This paper presents results of monitoring grinding processes with on-the-machine measurement of surface roughness by using nux ratios of scattered lights. A compact, on-the-machine surface roughness sensor. which consists of a diodelaser and several optic units. is developed. The control unit is also developed. The developed sensor together with the controller is applied for monitoring grinding processes of two different grinding machines. Experimental results show that the nux ratios and their standard deviations measured by the developed sensor over the entire ground surface are useful for monitoring grinding conditions. In particular, the sensor and the control unit are proved to be useful for monitoring grinding processes in order to detect abnormal grinding conditions and dressing time.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.2
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• pp.61-66
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• 2000

In this paper, we discuss the machining characteristics of HDD glass. Glass is now being used globally as a data storage device, Such glasses are usually machined by lapping by this technique requires a long machining time, resulting in low productivity, For this reason, we examine the possibility of EILD grinding in HDD glass workpieces, A move to ELID grinding may result in substantial cost reduction. Our purpose is to investigate the grinding characteristics of HDD glass in ELID grinding. The bonding materials for fixing the abrasives of cast iron, cobalt and bronze are applied, and grinding conditions such as rotation speed and feeding are varied. Results show that with the use of ELID, mirror surfaces can be achieved with high efficiency.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.2
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• pp.106-113
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• 1991

A diamond grinding wheel is generally used to grind hard and brittle materials, such as advanced ceramics. It is, however, quite difficult to dress a diamond grinding wheel efficiently because of its high degree of hardness. In this study, some investigations are carried out to increase dressing efficiecy of resinoid bonded diamond grinding wheel. Dressing forces are measured over a wide range of dressing conditions, and SEM observation of a grinding wheel is carried out. Special attention is paid to comparison between stick method and rotary brake method. Results obtained in this study provide useful information determining reguired dressing time, and for choosing efficient dressing condition for diamond grinding wheel.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.5
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• pp.493-498
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• 2013

The present study treats the optimization process for a non-linear grinding system with dual time delay, mainly from the energetic viewpoint. To this end, the stability of the grinding system is investigated first with regard to the grinding wheel rotation speed. The concept of grinding energy density is newly proposed as the primary figure of merit and this quantity is evaluated at various stable and limit cycle conditions. The computational results show that simple monotonic trend in energy density is observed under stable conditions, whilst rather complicated behaviors can appear when the conditions are associated with limit cycle oscillations. Finally, the relations between the vibration amplitude and the energy density and their implications on the engineering decision/compromise are discussed.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.84-87
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• 2001

A demand for the aggregates is increasing in the field of civil and architectural industry and so on. In these industries, the particle size and shape of aggregates are important factors and especially spherical or rounded particles are desired. In Japan, waste glass is used as one of the aggregate materials for the pavement or the construction. In this study based on the frictional action of material on each other, an autogenous grinding of silica glass with a stirred mill were carried out in order to eliminate flakelike or squarish particles and get spherical or rounded ones for aggregate materials. The autogenous grinding experiments were conducted by applying loads to the particle layer of silica glass. The particle shape was evaluated by the shape index, N/T and the degree of circularity, Ψ$_{ci}$ . The unfractured particles (20~13mm) were evaluated by N/T and Ψ$_{ci}$ , and the products (finer than 10${\mu}{\textrm}{m}$) by Ψ$_{ci}$ . As a result, N/T of the unfractured particles decreased with an increase of grinding time. Ψ$_{ci}$ of the unfractured particles and the products increased with an increase of grinding time (; progress of grinding), and became almost constant in the long time grinding. These tendencies were not changed by the applied load on the particle layer, but the limit value of Ψ$_{ci}$ at the products were varied with the applied load.plied load.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.125-130
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• 1994

Recently,manufacturing work been transformed to small acale production from with various items to act up to user's expectation from mass production with a little items required in the past. The FMS using NC type mother machinaries has been applied actively also in domestic manufacturing line to meet thus tendancy, but there are many machining troubles occured in work process not be settled yet. Nowdays high efficiency has been required no less than high precision in grinding work for the improvement of productivity. In this study, to represent more advanced FMS can be adapted to thus situation In-process type monitoring method using AE and Current sensors is suggested to investigatethe machining condition in grinding process. As results from this experimental study, is is recoqnized well that grinding conditions and dressing point of in time can be estimated effectively using monitoring method suggested. Furthermore, surface shape of grinding wheel on voluntary point of in time can be predicted indirectly through the observation and comparison of AE signal waveform obtained as performance of continuous dressing work.

• Journal of Ceramic Processing Research
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• v.23 no.4
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• pp.436-442
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• 2022

Gallium nitride (GaN) substrates were ground in two different grinding wheel abrasive sizes of 270 and 800-mesh, and thechange in surface morphologies of the substrates and the depth of subsurface damage (SSD) were observed. With the 800-meshgrinding wheel, the surface roughness (SR) and the depth of SSD of the sample tended to decrease, which was not the casewith the 270-mesh grinding wheel. In the X-ray rocking curve, the sample exhibited some compressive stress with the 270-meshgrinding wheel, but with the 800-mesh grinding wheel, it demonstrated the occurrence of tensile stresses in the sample and adecrease in full width at half maximum (FWHM), which confirms an improvement in the crystallinity. In the Raman spectra,the compressive stress of the 270-mesh grinding wheel and the tensile stress of the 800-mesh grinding wheel were confirmedthrough peak shifts. Photoluminescence (PL) spectra confirmed that the intensity ratio of the yellow luminescence increasedat the 800-mesh grinding wheel, and a blue shift occurred further. These results indicate that the SR and the depth of SSDwere proportional to the abrasive grain size of the grinding wheel. At the same time, the increase in PL intensity at specificpeak positions indicates that the stress stemming from the grinding process was concentrated at the crystal surface. The abovemechanism is illustrated in a schematic diagram, which confirms the possibility of improving the grinding efficiency andsubsequent polishing processes in future applications.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.850-853
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• 2004

The development of 3D CAM system for the manufacturing of end mills becomes a key approach to save the time and reduce cost for end mills manufacturing. This paper presents the calculation and simulation of end mill tools CNC machining bases on 5-axes CNC grinding machine tool. In this study describes the process of generation and simulation of grinding point data between the tool and the grinding wheels through the machined time. Depend on input data of end mill geometry, wheels geometry, wheel setting, machine setting the end mill configuration and NC code for machining will be generated and visualized in 3 dimension before machining. The 3D visualizations of end mill manufacturing was generated by using OpenGL in C++. The development software was designed by using Microsoft Visual C++, which has many advantages for users, saving time and reducing manufacturing cost.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.54-59
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• 2012

This study dealt with effect of the grinding in SCM420H planetary gears. The hardness, tooth profile, lead and roughness of the gear surface can be improved by grinding process. Therein, the grinding techniques are widely used especially as one of the physical surface improvement methods. As the results, the gear grinding process reduced vibration and noise, and increased the life of the gear. And the gear grinding improved the surface of gear tooth in a short time and low cost, thus, it is a very important process in manufacturing industry. But nowadays, it is hard to find the detail information of gear grinding process. The test piece is a planetary gear which is used in the industrial machine. The manufacture process of the test piece contains hobbing, shaving, carburizing and grinding. This study investigated the effect of the grinding process to the physiognomy and the fatigue strength of test piece which was made by SCM420H.