• Title/Summary/Keyword: Grinding conditions

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Evaluation of Pre-estimation Model to the Inprocess Surface Roughness for Grinding Operations

  • Kim, Gun-Hoi
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.4
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    • pp.24-30
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    • 2002
  • In grinding operations, one of the most important problems is to increase efficiency of process. In order to achieve this purpose, it is necessary to administer the tool lift of grinding wheel and to optimize grinding conditions. Frequently dressing result in lowering the process efficiency remarkably and makes production cost high. On the other hand, grinding with a worn wheel causes the workpiece surface roughness to increase and often results in the occurrence of such troubles as chatter vibration and homing.

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

  • 원종호;김건희;안병민;박순섭;이진오
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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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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Determination of decision of wheel life using grinding power (연삭동력을 이용한 숫돌수명 판정)

  • 이상태
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.204-209
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    • 1999
  • The dressing time monitoring in cylindrical grinding is very important with respect to machining efficiency. Therefore, the purpose of this paper is to determine the wheel life by monitoring behavior of grinding power for Wa, 19A and GC. For this purpose, we investigated indirectly the attritious wear of grain edge, the loading of grinding wheel and the breakage of grain through the grinding power and the surface roughness under various grinding conditions. From obtained the results, the relationship between the wheel life and the average sectional chip area is examined to guide for the determination of dressing time.

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Cut-off Grinding Characteristics of the Carbon Fiber Epoxy Composite Materials (탄소 섬유 에폭시 복합재료의 절단 연삭 특성)

  • Kim, Po-Jin;Choe, Jin-Gyeong;Lee, Dae-Gil
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.2 s.173
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    • pp.338-346
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    • 2000
  • Although the net-shape molding of composites is generally recommended, molded composites are frequently required cutting or grinding due to the dimensional inaccuracy for precision machine elements . During the composite machining operations such as cutting and grinding, the temperature at the cutting point may increase beyond the allowed limit due to the low thermal conductivity of composites, which might degrade the matrix of composite. Therefore, in this work, the temperature at the cutting point during cut-off grinding of carbon fiber epoxy composites was measured. The cutting force and surface roughness were also measured to investigate the cut-off grinding characteristics of the composites. The experiments were performed both under dry and wet grinding conditions with respect to cutting speed and feed rate. From the experimental investigation, the optimal conditions for the composite cut-off grinding were suggested.

Analysis and Optimization of Grinding Condition by Response Surface Model (반응표면모델(RSM)에 의한 평면연삭조건 최적화 및 평가)

  • Kim S.O.;Kwak J.S.;Koo Y.;Sim S.B.;Jeong Y.D.;Ha M.K.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1257-1260
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    • 2005
  • Grinding process has unique characteristics compared with other machining processes. The cutting edges of the grinding wheel don't have uniformity and act differently on the workpiece at each grinding. The response surface analysis is one of various methods for optimizing and evaluating the process parameters to achieve the desired output. In this study, the effect of the grinding parameters on outcomes of the surface grinding was analyzed experimently. To predict the grinding outcomes and to select the grinding conditions before grinding, the second-order response surface models for the grinding force and the surface roughness were developed.

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Comparison of 3 Typical methods for ultra-precision grinding (가공방식에 따른 초정밀 연삭의 비교)

  • Park, Soon-Sub;Lee, Ki-Young;Kim, Hyoung-Mo;Lee, Jae-Seol
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.6 no.3
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    • pp.9-15
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    • 2007
  • Three methods for grinding: cross grinding, slanted tool axis grinding and parallel grinding, were carried out to study the machinability of tungsten carbide mold for glass formed aspherics lens. In our research, the optimum grinding conditions were investigated in terms of feed-rate, relative velocity of wheel and work piece, tool marks and surface roughness. It is shown that cross grinding are most effective in removal ratio but poor in surface roughness. In addition, tool marks of each method were differentiated on direction and shape.

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Characteristic of Mirror Surface ELID Grinding of Large Scale Diametrical Silicon Wafer with Rotary Type Grinding Machine (로타리 연삭에 의한 대직경 Si-wafer의 ELID 경면 연삭특성)

  • 박창수;김원일;왕덕현
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.5
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    • pp.58-64
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    • 2002
  • Mirror surface finish of Si-wafers has been achieved by rotary in-feed machining with cup-type wheels in ELID grinding. But the diameter of the workpiece is limited with the diameter of the grinding wheel in the in-feed machining method. In this study, some finding experiments by the rotary surface grinding machine with straight type wheels were conducted, by which the possible grinding area of the workpiece is independent of the diameter of the wheels. For the purpose of investigating the grinding characteristics of large scale diametrical silicon wafer, grinding conditions such as rotation speed of grinding wheels and revolution of workpieces are varied, and grinding machine used in this experiment is rotary type surface grinding m/c equipment with an ELID unit. The surface ground using the SD8000 wheels showed that mirror like surface roughness can be attained near 2~6 nm in Ra.

Mirror Surface ELID Grinding of Large Scale Diametral Silicon Wafer with Straight Type Wheel (스트레이트 숫돌에 의한 대직경 Si-wafer의 ELID 경면연삭)

  • 박창수;김경년;김원일
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.946-949
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    • 2001
  • Mirror surface finish of Si-wafers has been achieved by rotary in-feed machining with cup-type wheels in ELID grinding. But the diameter of the workpiece is limited with the diameter of the grinding wheel in the in-feed machining method. In this study, some grinding experiments by the rotary surface grinding machine with straight type wheels were conducted, by which the possible grinding area of the workpiece is independent of the diameter of the wheels. For the purpose of investigating the grinding characteristics of large scale diametral silicon wafer, grinding conditions such as rotation speed of grinding wheels and revolution of workpiece are varied, and grinding machine used in this experiment is rotary type surface grinding m/c equipped with an ELID unit. The surface ground using the SD8000 wheels showed that mirror like surface roughness can be attained near 2~6nm in Ra.

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Temperature Distribution of Workpiece Varying with Grinding Condition (연삭조건 변화에 따른 가공물의 온도 분포)

  • Ha, Man-Kyung;Kwak, Jae-Seob;Kwak, Tae-Kyung
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.9
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    • pp.59-65
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    • 2002
  • Grinding temperature between a grinding wheel and a workpiece surface, rising rapidly during a machining operation, has bad effects on a surface integrity such as the burning, the residual stress and the crack. In this study, the temperature distribution was obtained briefly by the finite element method and the grinding temperature of a workpiece varying with the grinding condition was measured experimentally. For obtaining the grinding temperature, a thermocouple method was applied. Three thermocouples were inserted in a surface of each workpiece. Changed grinding conditions were the depth of cuts, the feedrate, the dry and wet grinding, the up and down grinding and the number of pieces.

A Study on the Grinding of Titanium Alloy Part 1 : Grinding force, Specific grinding energy, Surface roughness, G-ratio (티타늄 합금의 연삭에 관한 연구 Part 1: 연삭력, 비연삭에저니, 표면거칠기 , 연삭비)

  • Kim, S. H.;Lim, J. G.;Ha, S. B.;Choi, H.;lee, J. C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.870-874
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    • 2000
  • This investigation reports the grinding characteristics of titanium alloy(Ti-6Al-4V). Grinding experiments were performed at various grinding conditions and the grinding forces and specific grinding energies were measured to investigate the grindability of titanium alloy with the three different wheels including Diamond, Green carbide and Alumina. To investigate the grinding characteristics of titanium alloy grinding force, force-ratio, specific grinding energy and grinding -ratio, were measured. Surface roughness was also measured with tracer and the ground surfaces were observed with SEM. Force-ratio of grinding of titanium alloy was very lower than that of grinding of SKD-11. Specific grinding energy are almost five times larger and rougher surface was obtained in titanium grinding.

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