• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.59-64
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• 1998

We need to achieve th mass product through methods of higher efficient, higher precise manufacturing process than those of existing precision abrasive machining. Thus, this study is to develop mirror-like surface machining technique of outer diameter of the piston pin by the compound magneto-electrolytic abrasive polishing system. The procedure of machining is followed as first, fulfill the pre-processing by cylindrical grinder, second, complete mirror-like surface by the method of magneto-electrolytic abrasive polishing used CBN non-woven abrasive pads. In this study, it was found that the best suitable conditions of mirror-like surface polishing were that the electrode density was 0.1A/$\textrm{cm}^2$, the applied pressure 1.5kgf/$\textrm{cm}^2$, the feed rate 0.5mm/rev, and the rotoation velocity of workpiece 80rpm, and that the surface roughness was reduced in this conditions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.274-279
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• 2011

In this study, new abrasives that were composed of iron powder and carbon nanotube (CNT) particle were attempted to be abrasives for magnetic abrasive polishing. Because the CNT particles itself are very small ones with high hardness and magnetic strength, these properties are effective for magnetic abrasive polishing of nonmagnetic materials. As an experimental result for evaluating the machining characteristics in magnetic abrasive polishing, the CNT particles showed better performance than the conventional abrasives such as Fe and CBN powder.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.86-97
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• 1994

An experimental investigation is reported on the wear mechanism of CBN cutting tools. The cutting experiments were conducted on a lathe equipped with a tool dynamometer for cutting force measurement. The investigation of wear mechanism was executed by observing the worn tools using tool microscope and scanning electron microscope. Results indicate that the flank wear occurs dominantly by abrasive wear mode and the crater wear by adhesive wear mode. The results also indicate that the width of flank wear is closely related with the passive component of cutting force.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.14-20
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• 1998

Automatic finishing process requires the development of high efficient and precision abrasive machining method for dies and molds. This study describes the evaluation of the finishing characteristics, such as surfrace roughness, topography and material removal depth of the electrolytic mixed abrasive machining methods. Experimental setup is composed of 3 axis machining center, a newly developed finishing attachment with constant pressure, electrode and electrolytic bath. Finally, we achieved a successful result that surface roughness is $0.01\mu$m Ra and material removal depth is $120\mu$m using electrolytic(0.8A. 30V) mixed abrasive (#400 CBN, #320 SiC) machining method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.937-941
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• 1997

Utomatic finishing process requires the development of high efficient and precision abrasive machining method for die and molds. This study describes the evaluation of the finishing characteristics, such as sufrace roughness, topography and material removal depth, of the electrolytic chemical mixed abrasive machining method. Experimental setup is composed of 3 axis machining center, a newly developed finishing attachment with constant pressure, electrode and electrolytic bath. Finally, we achieved a successful result that surface roughness is 0.01 .mu. m Ra and material removal depth is 145 .mu. m after 100 times repeat-finishing using electrolytic (0.8A,30V) mixed abrasive (#400 CBN, #320 Sic) machining method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.3
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• pp.430-438
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• 1997

Deburring and edge finishing technology as the final process of machining operation is required for manufacturing of advanced precise conponents. But, deburring is considered as a difficult problem on going to the high efficient production and automation in the FMS. Removal of burr couldn't have a standard of its definition because of its various shapes, dimensions and properties and mostly depends on manual treatment. Especially, deburring for cross hole inside is very difficult owing to its shape passing through out perpendicular to a main hole. The electrochemical method is suggested as its solution in practical aspect. Therefore, electrochemical deburring technology needs to be developed for the high efficiency and automation of internal deburring in the cross hole. In this study, the new process in the eliminating burr inside cross hole, electrochemical deburring by the wheel electroplated with Cubic-Boron-Nitrade abrasives, is suggested. Its deburring mechanism is described and machining performances is investigated. Also, CBN electroplated wheel is designed and manufactured and then characteristics of electrochemical deburring are investigated through experiments. Overall electrochemical deburring performance against burr inside cross hole is examined in the various power sources such as peak current and direct current.

• Journal of the Korean Society for Heat Treatment
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• v.7 no.3
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• pp.199-205
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• 1994

The fracture characteristics and tool life of ceramics and WC, CBN cutting tool when turning heat treated steel STD11($H_RC$ 60) were investigated experimentally to clarify the machinability and optimum tool materials in cutting of difficult-to-cut material with high hardness. Forthermore, the behaviors of the tool wear and failure were examined with regard to cutting force. The hardened steel wore the cutting tool edge rapidily and increased the cutting forces, especially radial force. The tool was worn by the abrasive action. Flank Weat of $Al_2O_3-TiC$ ceramic and WC tool become relatively large and CBN & $Al_2O_3$, ceramic tool had a long life among the tool materials tested. The tool fracture patterns were just like minor cutting wear, flank wear, crater wear, notch wear, chipping. Flank wear rate was accelerated by occurrence of chipping. During the proceeding of machining, it was possible to foresee the catastrophic fracture of tool by abrupt increase of radial force.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.4
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• pp.491-497
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• 2010

The magnetic polishing is the useful method to finish some machinery fabrications by using magnetic power. This method is one of the precision techniques and has an aim for clean technology in the clean pipes. The magnetic abrasive polishing method is not so common in the field of machine that it is not known to widely. There are rarely researcher in this field because of non-effectiveness of magnetic abrasive. This paper deals with mediocritizing magnetic polishing device into regular lathe and this experiment was conducted in order to get the best surface roughness at low cost. This paper contains the result of experiment to acquire the best surface roughness, not using the high-cost polishing material in processing. In this paper, We could have investigated into the changes of the movement of magnetic abrasive grain. In reference to this result, we could have made the experiment which is set under the condition of the magnetic flux density, polishing velocity according to the form of magnetic brush.