• Journal of the Korean Society of Industry Convergence
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• v.8 no.1
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• pp.25-29
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• 2005

Titanium specially has high specific strength, excellent mechanical properties as fatigue strength and fracture ductility, good corrosion resistance, and therefore are broadly applied to the various fields. It is required the developmennt for the skills of wire-cut electrical discharge machining(WEDM), but the WEDMed surface was found to be worst due to the attached components of wire. Therefore precision maching method like lapping is necessary for getting high quilty surface. Roughness of lapped surface, surface hardness to each process depth and improved method of surface shape were stuided experimentally, by changing of grain size of diamond lap material and lapping pressure with constant speed in lapping process.

• Journal of Mechanical Science and Technology
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• v.19 no.8
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• pp.1576-1581
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• 2005

Generally, the optical components are fabricated by grinding, lapping, and polishing. And, those processes take long time to obtain such a high surface quality. Therefore, in the case of large optical component, the on-machine inspection (OMI) is essential. Because, the work piece is fragile and difficult to set up for fabricating and measuring. This paper is concerned about a swing-arm method for measuring surface profile of large optical concave mirror. The measuring accuracy and uncertainty for suggested method are studied. The experimental results show that this method is useful specially in lapping process with the accuracy of $3\~5\;{\mu}m$. Those inspection data are provided for correcting the residual figuring error in lapping or polishing processes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.1
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• pp.107-114
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• 2011

In this study, a correlation between the roughness of nanoscale lapping surface and its laser scattering pattern has been identified experimentally. The characteristics of laser scattering on a reflected surface are investigated, and a laser scattering mechanism is newly designed by adopting the dark-field method. Laser scattering patterns resulting from nanoscale lapping shape are in the shape of crossed irregular lattice. In addition, optimum laser scattering images are obtained by the design of experiment, and the roughness of nanoscale lapping surface is estimated using regression analysis certain useful features of the laser scattering patterns. The results of fifty experiments on three types of nanoscale lapping surfaces show that the roughness of nanoscale lapping surfaces can be accurately estimated by the proposed mathematical modeling method.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.150-153
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• 2006

The purpose of this research is focused on evaluating the flexural behavior of reinforced concrete beam having 22mm diameter re-bars by lapping methods. To compare the existent lapping method with mechanical lapping methods, four cases of concrete beams were tested to be failed flexurally by monotonic loading. Based on test results, the relations between load and displacement, ductility, maximum load was comparatively analyzed. The structural performance on four cases of members were evaluated.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.3
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• pp.41-46
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• 2008

Generally optical components are fabricated by grinding, lapping and polishing processes. Those processes take long time to obtain optical high surface quality. In the case of large optical components, the on-machine measurement is strongly recommended because the workpiece is fragile and difficult to set up for fabricating and measuring. This paper is concerned about a swing-arm mechanism which can be used for on-machine measurement of a surface profile with a sensing probe end-effect, and also for grinding or lapping the surface with a corresponding tool. The measuring accuracy and uncertainty using a swing arm type profilometer have been studied. The experimental results show that this method is useful specially in lapping process with the accuracy of $5{\mu}m$. Those inspection data are provided for correcting the residual figuring error in next processes.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2509-2517
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• 1993

Lapping is a very complicated and random process resulting from the variation of abrasive grains in its sizes and shapes and from the numerous factors having an effect on the process quality. Thus it needs to be analyzed by experimental method rather than by theoretical method to obtain the relative effects of factors quantitatively. In this study, cylindrical lapping experiment designed by Taguchi's L8 orthogonal array was performed and analyzed by Yates' ANOVA table. As a result, effective factors and interaction effects were identified and discussed. Also the optimal factor combination to obtain the largest improvement of surface roughness was selected and confirmatory experiments were peformed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.381-385
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• 2006

This research introduces easy tool manufacturing method regarding tool manufacturing procedure. In the conventional method, wire cutting machining and lapping operation of corner and render region were performed after shrink-fitting to ensure the accuracy of gear profile. But lapping operation is very difficult due to corner and render is located deep inside of die. In this research, wire cutting operation was performed after $1^{st}$ ring was shrink-fitted to ease lapping operation and increase the accuracy of corner radius. Before $2^{nd}$ ring fitting, lapping was completed. Elastic deformation amount due to $2^{nd}$ ring fitting and cold forging was calculated through finite element analysis and wire cutting specification was offset in that amount. Comparison of gear dimension between analysis and forged part ensures the validity of new manufacturing methods.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.956-959
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• 2001

In die and mould industry, major material such as cemented carbide is broadly used for increasing the life time and decreasing the cost. It is also required the development for the skills of wire-cut electrical discharge machining(WEDM), but the WEDMed surface was found to be worst due to the attached components of wire. Precision machining method like lapping is necessary for obtaining high quality surface. The lapping compound such as Al2O3 and SiC and cast iron lap can be used for lapping process. The components of Cu and Zn were found WEDMed surface of the specimen. As the result, the low quality of precision was obtained and the heat damage layer of the specimen was occurred. The value of surface hardness was deteriorated, and therefore finish process was required.

• Journal of the Korean Ceramic Society
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• v.36 no.4
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• pp.417-424
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• 1999

Laser lapping of diamond films is performed with focused beam of copper vapor laser. Both spherical and rod-shape laser beam are used. Diamond surface is scanned at various scan speeds(0,125, 0.5, 0.75 mm/sec) and baem shifts (5, 10, 20, 40, 100$\mu\textrm{m}$) At 0.125 mm/sec 10$\mu\textrm{m}$ scan condition the level difference of di-amond surface of about 700$\mu\textrm{m}$ over 20 mm is reduced to 200$\mu\textrm{m}$ In addition surface roughness is also im-proved from 3.53$\mu\textrm{m}$ to 2.47$\mu\textrm{m}$ at 5$\mu\textrm{m}$ beam shift. But at higher beam shift than 10$\mu\textrm{m}$ laser scan makes the surface rougher which is considered to be due to the non uniform spatial distribution of laser en-ergy. It is concluded that homogenized laser beam with high average power is needed for large area laser lapping of diamond films at appreciable rates.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.303-304
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• 2007