• 제목/요약/키워드: Surface Finish Technology

검색결과 147건 처리시간 0.044초

알루미나 연삭표면 특성에 관한 연구 (A Study on the Surface Characteristics n the Alumina Grinding)

  • 하상백
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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    • pp.519-524
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    • 1999
  • To manufacture alumina products, sintering and grinding process are needed. In Al2O3 grinding, macro/micro surface fracture and cracks are easily occurred on the ground surface because of its high brittleness. In view point of fatigue fracture, surface profile produced by grinding is considered as notches. Therefore, it was reasonable that magnitudes and shapes of surface profiles effects on fatigue strength and life. Particularly, surface finish of Al2O3 which have high hardness and brittleness have an effect on fatigue strength. In this paper, some experiments are carried out to examine influence of grinding conditions to magnitude and shape of surface profile as well as the relationships of Ra, Rmax, Rmax/Ra, and Ku. Through the experimental results, It is found that Ra and Rmax was affected by grinding conditions, but Rmax/Ra and Ku was not. There are linear relations between Ra and Rmax, and between Rmax/Ra and Ku.

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EVA를 이용한 가변 용착 쾌속 조형 공정의 개발 (Development of Variable Deposition manufacturing for Ethylene Vinyl Acettecopolymer)

  • 이상호;신보성;정준호;안동규;양동열
    • 한국정밀공학회지
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    • 제17권9호
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    • pp.189-195
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    • 2000
  • RP techniques have their unique characteristics according to the working principles : star-stepped surface of parts due to layer-by-layer stacking low build speed caused by line-by-line solidification to fish one layer and post processing to improve surface finish etc The objective of this study is to propose a new RP technique Variable Deposition Mnanufacturing (VDM) which can make up for the disadvantages of the existing RP techniques and to develop an apparatus to implement the technique. The proposed process can greatly reduce the build time and improve the surface finish of parts generated. Experiments are carried out to obtain the range of temperature of molten material to maintain its fluidity and to investigate the effect of gas cooling on the preservation of the slopes. Some simple shapes such as a line-shape an S-shape and a circle-shape are fabricated from Ethylene Vinyl Acetatecopolymer(EVA) In order to examine the applicability of VDM to more general shapes a tensile specimen and a yo-yo shape were manufactured by the proposed RP method using EVA material as a trial approach. The current basic study shows a high potential of practical use of the proposed VDM process to prototyping of a general three-dimensional shape.

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다기공홈형 단속지석의 개발에 관한 연구(I) - 단속지석의 설계, 제작 및 연삭특성 - (Development of Discontinuous Grinding Wheel with Multi-Porous Grooves(I) -Design, Manufacture and Grinding Characteristics of Discontinuous Grinding Wheel-)

  • Kim, J.D.;Jin, D.X.;Lee, Y.S.
    • 한국정밀공학회지
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    • 제13권8호
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    • pp.52-59
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    • 1996
  • Conventionally, grinding of stainless steel, aluminium ally, copper alloy, and titanum alloy are difficult to obtain the high quality finish, because they have the mechanical properties such as low hardness, high toughness which result in the loading of wheel and the poor surface finish. Inorder to perform the grinding operations for these sorts of materials easily, the discontinuous grinding wheel with multi-porous grooves has newly been developed. The multi-porous grooves were formed during wheel production. This discontinous grinding wheel increases the grinding performance. It is desirable to use the discontinuous grinding wheel when grinding materials wiht high efficiency and accuracy which is impossible by conventional wheels. In this paper, the constructing and manufacturing method of grinding wheel with multi-proous grooves are explained, and the grinding charateristics of discontinuous grinding wheel are also illustrate.

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Design optimization for analysis of surface integrity and chip morphology in hard turning

  • Dash, Lalatendu;Padhan, Smita;Das, Sudhansu Ranjan
    • Structural Engineering and Mechanics
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    • 제76권5호
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    • pp.561-578
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    • 2020
  • The present work addresses the surface integrity and chip morphology in finish hard turning of AISI D3 steel under nanofluid assisted minimum quantity lubrication (NFMQL) condition. The surface integrity aspects include microhardness, residual stress, white layer formation, machined surface morphology, and surface roughness. This experimental investigation aims to explore the feasibility of low-cost multilayer (TiCN/Al2O3/TiN) coated carbide tool in hard machining applications and to assess the propitious role of minimum quantity lubrication using graphene nanoparticles enriched eco-friendly radiator coolant based nano-cutting fluid for machinability improvement of hardened steel. Combined approach of central composite design (CCD) - analysis of variance (ANOVA), desirability function analysis, and response surface methodology (RSM) have been subsequently employed for experimental investigation, predictive modelling and optimization of surface roughness. With a motivational philosophy of "Go Green-Think Green-Act Green", the work also deals with economic analysis, and sustainability assessment under environmental-friendly NFMQL condition. Results showed that machining with nanofluid-MQL provided an effective cooling-lubrication strategy, safer and cleaner production, environmental friendliness and assisted to improve sustainability.

엑폭시 수지의 절삭가공시 표면거칠기에 관한 연구 (Study on the Surface Roughness of the Epoxy resins))

  • 김희남
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1996년도 추계학술대회 논문
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    • pp.64-74
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    • 1996
  • The meachanism for cutting epoxy resins specimens which were specially provided was experimentally investigated to obtain a fine surface finish. the specimens were cut the three-dimensional undrer dry conditions using a lathe. the relationship between the topography of the cut surface due to the change rate of temperature of the cutting condition using sintered carbides (P20, K10, KT150) was investigated. the main results obtained are as follows: 1) The change rate of temperature of the cutting edge is increased in nearly proportion ot cutting speed feed rate depth of cut. 2)The profile of surface roughness were regulated k10 but irregulated P20 KT150. 3) The surface roughness value decreased K10 rather than P20 KT150. 3) The surface roughness value decreased K10 rather than P20 KT 150.4)The cutting resistance increased thrust force rather than cutting force due to the visco-elastic material of epoxy resins.

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세라믹연삭에 있어서 표면품위에 관한 연구 (A Study on the Surface Intigrity of Grinding of Ceramics)

  • 하상백;임종고;김성헌;최환;이종찬
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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    • pp.337-342
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    • 2000
  • Experimental investigations were carried out to find the characteristics of grinding of ceramics. Grinding mechanisms of ceramics were inspected through the microscopic examination. It has been found that the specific grinding energy of ceramics is relatively low as compared to that of steels. The specific grinding energy affects the surface roughness and the residual stress of ground surface. The experimental results indicate that the rougher surface finish and higher compressive residual stress are obtained at lower specific grinding energy. The surface roughness and the residual stress of the ground surface have significant effects on the strength of ground piece of ceramics.

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Alloy 600의 결정립계 산화에 대한 표면 변형의 영향 (Effects of Surface Deformation on Intergranular Oxidation of Alloy 600)

  • 하동욱;임연수;김동진
    • Corrosion Science and Technology
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    • 제19권3호
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    • pp.138-145
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    • 2020
  • Immersion tests of Alloy 600 were conducted in simulated primary water environments of a pressurized water reactor at 325 ℃ for 10, 100, and 1000 h to obtain insight into effects of surface deformation on internal and intergranular (IG) oxidation behavior through precise characterization using various microscopic equipment. Oxidized samples after immersion tests were covered with polyhedral and filamentous oxides. It was found that oxides were abundant in mechanically ground (MG) samples the most. The number density of surface oxides increased with time irrespective of the method of surface finish. IG oxidation occurred in mechanically polished (MP) and chemically polished (CP) samples with thin internal oxidation layers. However, IG oxidation was suppressed with relatively thick internal oxidation layers in MG samples compared to MP and CP samples, suggesting that MG treatment could increase resistance to primary water stress corrosion cracking (PWSCC) from the standpoint of IG oxidation. As a result, appropriate surface treatment for Alloy 600 could prevent oxygen diffusion into grain boundaries, inhibit IG oxidation, and finally induce its high PWSCC resistance.

금형연마작업을 위한 5축 CAM 시스템 (A five-axis CAM system for free-surface grinding)

  • 서석환;이민석;김두형
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.1024-1030
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    • 1993
  • In manufacturing press die with free surface, grinding operation is an important post process for surface finish and dimensional accuracy. With the advancement of NC technology. surface grinding operation is increasingly replaced by the gantry type manipulator. As the mechanics for grinding operation is different from machining operation, conventional CAM system for machining operation is hard to apply. In this. paper, we develop a five-axis CAM system by which an efficient gantry trajectory can be planned and verified. The developed system consists of four conceptual modules; namely CAD, PROCESS. CAM, and ANALYSIS. In the CAD module, the machined surface is represented by CL-data or surface modeler, and process parameters are specified by the PROCESS module. Then, the CAM module generates a series of grinding paths based on the grinding mechanics together with process databases for tool spaces and grinding conditions. The generated paths are verified via ANALYSIS module. Validation via real experiments is left for further study.

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유도가열 및 근적외선 가열방법에 의한 표면처리 강판 도포층의 가열 및 건조 특성 (Heating & Drying Characteristics of Coating Layer by Induction Heating and Short-wave Infrared Heating)

  • 김태수;양재원
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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    • pp.249-257
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    • 2004
  • Drying and curing characteristics of PCM resins using the induction heater and short-wave infrared emitter module was studied to develop a compact oven system for the high speed CCL and post-treatment equipment. Drying of the polyester resins using the induction heater and infrared heater showed that the blistering tendency of polyester resin coating increased regardless of additives and colors of resins as the heating rate and/or dry film thickness increased. The blistering of polyester resin coating layer occurred when the heating speed was over than $25^{\circ}C/sec$ for the dry film thickness of $19\~20um$, which is the typical thickness of finish coating in CCL. So did it when the heating speed was over than $40^{\circ}C/sec$ for the dry film thickness over than 10 um. The heating efficiency of paint coated steels by the infrared heating was strongly dependent on the colors of paint coating and generally increased for the dark surface and/or coating. But the faster drying of the PCM resin coatings increased the blistering tendency of coating layer. The blistering limit for the typical finish coating by the infrared heating was estimated as the heating rate slower than $20^{\circ}C/sec$ regardless of colors of PCM resins.

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기능성 가공된 견직물의 태 (Objective Hand of High-performance Silk Fabrics)

  • 김현아;유효선
    • 한국의류학회지
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    • 제34권5호
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    • pp.754-764
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    • 2010
  • Most silk fabrics are produced only after the degumming process to make the best use of the properties and have restricted silk processing that do not hinder their performance. However, considering the highly increased preference for natural fibers and the shortage of raw silk, high-quality upgraded silk product functions are required by the development of a processing technology and a good design. This study analyzes the changes with the samples by the functional finish such as softening finishing, wash and wear, tannin weighting by measuring the objective hand of scoured silk and three finished ones using KES-FB. As a result, the change of objective hand of finished silk fabrics that improves functionality was analyzed and compared. The increase of KOSHI after the finish became stiffer show that the silk fabric samples are appropriate for summertime clothes with the retention of a certain clothing climate for the body. The stiffness of finished fabrics for the normal had a closer relationship with the density of fabrics than the type of finishing. The samples (after the softening finishes) maintain better elasticity according to the properties of the softener and the finishing agent. Although the specimens of this study were thin fabrics, their elasticity against compression increased after the softening finishes and became softer than degummed silk. The surface properties of georgette were changed by all types of finishing.