• 제목/요약/키워드: Material Removal rate

검색결과 593건 처리시간 0.032초

CBN휠에 의한 5종 재료의 연삭 특성 비교 (The Grinding Characteristics of 5 kind metals for CBN Wheel)

  • 원종호;김건희;안병민;박순섭;이진오
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.925-929
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    • 2001
  • Ultra-abrasives such as diamond and CBN have used to maintain accuracy and form deviation for superalloy etc. This study contains the dry cylindrical grinding of metals with Vitrified-bond CBN wheel and Resinoid-bond CBN wheel. For various conditions of grinding speed, workpiece speed, grinding depth and feed speed of table, the grinding resistance, the surface roughness, and the material removal are measured and discussed.

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CBN 휠의 연삭특성에 관한 비교연구 (A study Grinding Characteristic of CBN Wheel)

  • 안병민;원종호;김건희
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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    • pp.315-320
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    • 2001
  • Ultra-abrasives such as diamond and CBN have used to maintain accuracy and form deviation for superalloy etc. This study contains the dry cylindrical grinding of metals with Vitrified-bond CBN wheel and Resinoid-bond CBN wheel. For various condition of grinding speed, workpiece speed, grinding depth and feed speed of table, the grinding resistance, the surface roughness, and material removal are measured and discussed.

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WEDM 가공특성에 대한 방전액의 전기전도율의 영향 (Electrical Conductivity of Dielectric on WEDM Characteristics)

  • 김창호;여홍태
    • 대한기계학회논문집A
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    • 제27권10호
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    • pp.1800-1808
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    • 2003
  • This work deals with the electrical conductivity of dielectric on output parameters such as metal removal rate and surface roughness value of a carbon steel(SM25C) and sintered carbides cut by wire-electrical discharge machining(W-EDM). Dielectric has several functions like insulation, ionization, cooling, the removal of waste metal particles. The presence of minute particles(gap debris) in spark gap contaminates and lowers the breakdown strength of dielectric. And it is considered that too much debris in spark gap is generally believed to be the cause of arcing. Experimental results show that increases of cobalt amount in carbides affects the metal removal rate and worsens the surface quality as a greater quantity of solidified metal deposits on the eroded surface. Lower electrical conductivity of the dielectric results in a lower metal removal rate because the gap between wire electrode and workpiece reduced. Especially, the surface characteristics of rough-cut workpiece and wire electrode were analyzed too. Debris were analyzed also through scanning electron microscopy(SEM) and surface roughness tester. Micro cracks and some of electrode material are found on the workpiece surface by energy dispersive spectrometer(EDS).

소재제거율을 일정하게 한 NURBS 보간기에서 절삭성 고찰 (Research on Machineability in NURBS Interpolator Considering Constant Material Removal Rate)

  • 고태조;김희슬
    • 한국정밀공학회지
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    • 제21권12호
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    • pp.60-66
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    • 2004
  • Increasing demands on precision machining of 3D free-form surface have necessitated the tool to move smoothly with varying feedrate. To this regard, parametric interpolators such as NURBS (Non-Uniform Rational B-Spline) interpolator have been introduced in CNC machining system. Such interpolators reduce the data burden in NC code, increase data transfer rate into NC controller, and finally give smooth motion while machining. In this research, a new concept to control cutting load in NURBS Interpolator was tried based on the curvature of curve. This is to protect cutting tool, and to have good machinability. For proof of the system, cutting force and surface topography were evaluated. From the experimental results. the interpolator is good enough for machining a free-form surface.

실리카 입자의 형상과 표면 특성이 산화막 CMP에 미치는 영향 (Effect of shape and surface properties of hydrothermaled silica particles in chemical mechanical planarization of oxide film)

  • 정정환;임형미;김대성;백운규;이승호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.161-161
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    • 2008
  • The oxide film of silicon wafer has been mainly polished by fumed silica, colloidal silica or ceria slurry. Because colloidal silica slurry is uniform and highly dispersed composed of spherical shape particles, by which the oxide film polished remains to be less scratched in finishing polishing process. Even though the uniformity and spherical shape is advantage for reducing the scratch, it may also be the factor to decrease the removal rate. We have studied the correlation of silica abrasive particles and CMP characteristics by varying pH, down force, and table rotation rate in polishing. It was found that the CMP polishing is dependent on the morphology, aggregation, and the surface property of the silica particles.

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실험계획법을 이용한 최적연삭조건 (Optimal Grinding Condition Using the Design of Experiments)

  • 이대욱;오창진;김성청;김옥현
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.866-869
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    • 2000
  • To improve quality of the ground surface, we have to consider a number of parameters. But it is difficult to make experiment with many parameters. Most of all experiments try to search optimal grinding condition with conservative factors such as feed rate, depth of cut, wheel rotating speed, etc. But This paper attempts to view the significance of some different factors effecting on the surface roughness by introducing helical scan grinding method and material removal rate. The design of experiment is used to find the optimal grinding condition which minimizes the surface roughness value bout optical glass material. To analyze experimental results, ANOVA(ANalysis of VAriation) is used. Discussion on the result about helical scan grinding is also given.

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무성방전내에서 톨루엔 제거에 미치는 운전변수의 영향 (Effects of Operating Parameters on Toluene Removal in Dielectric Barrier Discharge Process)

  • 정재우;이용환;박경렬
    • 한국대기환경학회지
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    • 제18권3호
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    • pp.173-182
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    • 2002
  • We investigated the effects of operating variables, such as electrical. reactor and gas parameters on toluene removal and discharge property in the dielectric barrier discharge (DBD) process. The toluene removal was initiated with the energy transfer to the reactor by loading of voltages higher than the discharge onset value. The energy transfer and toluene removal increased with the applied voltage. Higher removal rate was observed with smooth surface electrode despite of lower energy transfer compared with the coarse electrode, because more uniform discharge can be obtained on smooth surface state. The decrease of dielectric material thickness enhanced the removal efficiency by increasing the discharge potential. The toluene removal efficiency decreased with the increase of the inlet concentration. The increase of gas retention time enhanced the removal efficiency by the increase of energy density. The oxygen and humidity contents seem to exert significant influences on the toluene removal by dominating the generation of electrons, ions, and radicals which are key factors in the removal mechanism.

알루미나 세라믹의 초음파가공 특성 연구 (A Study on the Ultrasonic Machining Characteristics of Alumina Ceramics)

  • 강익수;강명창;김창식;김광호;서용위
    • 한국기계가공학회지
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    • 제2권1호
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    • pp.32-38
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    • 2003
  • Engineering ceramics have many unique characteristics both in mechanical and physical properties such as high temperature hardness, high thermal, chemical and electrical resistance. However, its machinability is very poor in conventional machining due to its high hardness and severe tool wear. In the current experimental study alumina($Al_2O_3$) was ultrasonically machined using SiC abrasives under various machining conditions to investigate the material removal rate and surface quality of the machined samples. Under the applied amplitude of 0.02mm, 27kHz frequency, three slurry ratios (abrasives water by weight) of 11, 13 and 15 with different tool shapes and applied pressure levels, the machining was conducted. Using the mesh number of 240 abrasive, slurry ratio of 11 and static pressure of $25kg/cm^2$, maximum material removal rate of $18.97mm^3/mm$ was achieved with mesh number of 600 SiC abrasives and static pressure of $30kg/cm^2$, best surface roughness of $0.76{\mu}m$ Ra was obtained.

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수계 내 조류 제거를 위한 전기응집 운전 특성 평가 (Evaluation of Operation Parameters for the Removal of Algae by Electro-Coagulation)

  • 정권;김도군;김석구;김원재;고석오
    • 한국물환경학회지
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    • 제31권2호
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    • pp.94-102
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    • 2015
  • Electro-coagulation experiments were conducted with aluminum (Al) or iron (Fe) electrode in order to determine the optimal electrode material and operation conditions for algae removal. Al electrode showed higher removal rate of algae than Fe electrode because Al flocs have positive surface charges which electrostatically attract algae species having negative surface charges. Removal rate of algae and total phosphorous (T-P) was increased as current density and electrode area increases. It was also found that initial pH with neutral range was optimum for T-P removal by electro-coagulation. Bench-scale continuous flow experiments consisted of electro-coagulation reactor, agitation tank and settling tank were conducted. In electro-coagulation reactor, a large fraction of Al flocs were distributed to scum layer, due to the gas bubbles generated by electrolysis reaction. In agitation tank, most of Al flocs were settled and the optimal mixing intensity was found to be 50 rpm to achieve good settleability. The removal rate of algae was about 90-95%. Additionally, the removal rate of the T-P and COD was observed to be $73.8{\pm}8.0%$ and $75.0{\pm}3.8%$, respectively. Meanwhile, the removal rate of total nitrogen (T-N) was relatively low at only 24%.

화학-기계적 연마 공정의 물질제거 메커니즘 해석 Part II: 동적 시뮬레이션 (An Analysis on the Material Removal Mechanism of Chemical-Mechanical Polishing Process Part II: Dynamic Simulation)

  • 석종원;오승희
    • 반도체디스플레이기술학회지
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    • 제6권3호
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    • pp.1-6
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    • 2007
  • The integrated thermal-chemical-mechanical (TCM) material removal model presented in the companion paper is dynamically simulated in this work. The model is applied to a Cu CMP process for the simulation and the results of the three individual ingredients composing the model are presented separately first. These results are then incorporated to calculate the total material removal rate (MRR) of the Cu CMP. It is shown that the non-linear trend of MRR with respect to the applied mechanical power (i.e., non-Prestonian behavior), which is not well explained with the models established in principle on conventional contact mechanics, may be due to the chemical reaction(s) varying non-linearly with the temperature in the wafer.

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