• 제목/요약/키워드: Grinding of glass

검색결과 110건 처리시간 0.034초

초정밀 연삭기에 의한 사파이어의 나노가공 (A Study on the Nano Grinding of Sapphire by Ultra-Precision Grinder)

  • 김우순;김동현;난바의치
    • 한국공작기계학회논문집
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    • 제12권5호
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    • pp.40-45
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    • 2003
  • Optical and electronic industries are using lapping and polishing processing as a final finish rather than grinding, because they need more accurate parts of brittles non-metallic materials such as single crystals. Sapphire has been ground by the ultra-precision surface grinder having a glass -ceramic spindle of extremely-low thermal expansion with various cup-type resinoid-bonded diamond wheels of #400-#3000 in grain size. Sapphire can be ground in the ductile mode. And also, the surface roughness and grinding conditions has been clarified. The smooth surface of Sapphire less than 1nm RMS, 1nm Ra can be obtained by the ultra-precision grinding without any polishing process.

자성연마슬러리를 이용한 초미립 초경합금(WC-Co 18%)의 나노급 경면가공 특성 (Machining Properties to Nano-Level Mirror Surface Finishing for Fine Grained WC-Co 18% Alloy using Magnetic Polishing Slurry)

  • 곽태수
    • 한국세라믹학회지
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    • 제46권1호
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    • pp.102-107
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    • 2009
  • This study has been focused on an effective surface finishing method combining ELID (ELectrolytic In-process Dressing) and MAP (Magnetic Assisted Polishing) for the nano-precision mirror grinding of glass-lens molding mould. ELID grinding is an excellent technique for mirror grinding of various advanced metallic or nonmetallic materials. A polishing process is also required for elimination of scratches present on ELID grinded surfaces. MAP has been used as polishing method due to its high polishing efficiency and superior surface quality. It also presents some techniques for achieving the nanometer roughness of the hard material such as WC-Co, which are extensively used in precision tooling material.

개방형 금형을 이용한 유리 렌즈 성형 해석 (Finite Element Analysis of Glass Lens Forming Process Using Open Die)

  • 나진욱;임성한;전병희;오수익
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 춘계학술대회논문집
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    • pp.143-147
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    • 2003
  • Despite of outstanding optical performance of glass lens, glass lens have not been widely used because of poor productivity and high cost due to manufacturing process i.e. grinding, polishing. However, press-forming method of glass lens overcomes this disadvantage because of mass production. When glass lens is produced by press-forming method using closed die, it is needed that the volume of glass lens preform precisely measured in order to prevent incomplete products and to increase in life of die. The present paper shows the shortcoming of forming process with closed die, and performs FEM simulation of forming process with open die in order to overcome this shortcoming. The design parameter of open die is selected in standard of assembly with optical module and maintenance of optical performance. FEM simulation is carried out with selected parameter of open die and two basic preform. According to distribution of effective strain in glass lens, optical property of glass lens formed at each set of die and preform is compared.

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평행연삭과 자기연마에 의한 유리렌즈 성형용 코어 금형의 표면가공 특성 (Investigation for Mirror-surface Machining Properties of Mold Core of Glass Molding Press by Parallel Grinding and Magnetic Assistance Polishing)

  • 이용철;김경년;곽태수
    • 한국정밀공학회지
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    • 제27권12호
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    • pp.22-27
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    • 2010
  • The usage of ultra-precision machining is increasing by the manufacturing of precision optical elements such as camera lens, laser printer, CD player, DVD and microscope parts etc.. The WC alloy material is in wide use by mold core to improve the productivity and accuracy in manufacturing those precision parts. The WC alloy mould core can be machined effectively by the parallel grinding process which is an excellent technique for manufacturing of surface profile hard to machining materials such as the hardened metal alloy, Ceramics, Glass and so on. Magnetic assisted polishing as a final polishing process has also been utilized to obtain ultra-precision mirror surface with the elimination of traces presented on ground surface. It is able to deduce the optimal ultra-precision machining conditions of the WC alloy material from the experiment and analyses results.

DOE를 적용한 WC(Co 0.5%)의 최적 연삭가공조건 연구 (Study on Optimal Grinding Condition of Tungsten Carbide(Co 0.5%) using DOE)

  • 김현욱;정상화;차두환;안준형;김상석;김혜정;김정호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.221-222
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    • 2006
  • In recent years, the demands of the aspherical glass lenses increase since it is difficult to obtain the desirable performance in the plastic lens. Glass lens is manufactured by the forming with high precision mold core. This paper presents the analysis of optimal grinding condition of tungsten carbide(WC, Co0.5%) using design of experiments(DOE). The process parameters are turbin spindle, work spindle, feedrate and depth of cut. The experiments results are evaluated by MINITAB software.

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Glassy Carbon의 초정밀 가공 (Ultraprecision Machining of Glassy Carbon)

  • 황연;이현성;김혜정;김정호
    • 한국기계가공학회지
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    • 제11권3호
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    • pp.19-23
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    • 2012
  • Glassy carbon is widely used for high temperature melting process such as quartz due to its thermal stability. For utilizing Classy Carbon to glass mold press(GMP) optical lens, brittleness of Glassy Carbon is main obstacle of ultraprecision machining. Thus authors investigated ductile machining of Glassy Carbon adopting turning and grinding process respectively. From the experiments, ultraprecision turning surfaces resulted brittle crack in all machining conditions and ultraprecision grinding surfaces showed semi-ductile mode in small undeformed chip thickness conditions.

옥천 장석의 특성에 관한 연구 (A Study on the Character of Okchun Feldspar)

  • 최용식;이종근;이경희;이병하;김영호
    • 한국세라믹학회지
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    • 제27권2호
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    • pp.149-154
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    • 1990
  • Before benefication of Okchun feldspar, all kinds of Fe-compounds and mafic minerals which were included in feldspar were studied. Also to produce 30/140mesh products as glass materials, optimum grinding condition and degree of liberation were studied. Fe-compounds were Biotite and Limonite, and these were existed along the cleavage. Optimum grinding time was 2min. and at this time weight percent of 30/140mesh products was 72.7% and degree of liberation at this particle size was 91.5%.

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경취 재료의 ELID(Electrolytic In-Process Dressing) 경면 연삭 절단에 관한 연구

  • 김화영;안중환;부산대기계공학부
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.65-68
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    • 1995
  • A slicing method by thin diamond blade is widely usd slicing of hard and brittle materials such as ceramics,glass and ferrite etc.. In this study, a new slicing system which realizes highly efficient and mirror surface slicing was developed by applying ELID-grinding with metallic bond diamond blades and its performance was evaluated. Hard and brittle materials such as ceramics,glass and ferrite were used as workpiece. Metallic bond diamond blades with grit sizes #325 and #2000 were used. Experimental results show that highly efficient slicing and good mirror surface can be successfully obtained using the developed slicing system with ELID features.

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A Study on the Aspheric Glass tens Forming Analysis in the Progressive GMP Process

  • Chang, Sung-Ho;Lee, Young-Min;Shin, Kwang-Ho;Heo, Young-Moo
    • Journal of the Optical Society of Korea
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    • 제11권3호
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    • pp.85-92
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    • 2007
  • In the past, precision optical glass lenses were produced through multiple processes such as grinding and polishing, but mass production of aspheric glass lenses requiring high accuracy and having complex profile was rather difficult. In such a background, the high-precision optical glass molding pressing (GMP) process was developed with an eye to mass production of precision optical glass parts by molding press. In this paper, as a fundamental research to develop the multi-cavity mold for higher productivity of a progressive GMP process used in the fabrication of an aspheric glass lens, an aspheric glass lens forming simulation was carried out.