• Title/Summary/Keyword: Surface roughness

Search Result 4,104, Processing Time 0.185 seconds

Analysis of Surface Roughness by FFT Analyzer in Turning Operation (선반작업(旋盤作業)에서의 FFT Analyzer에 의한 표면(表面)거칠기 해석(解析))

  • Kim, Gyung-Nyun;Choi, Eun-Soon
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.12 no.3
    • /
    • pp.12-19
    • /
    • 1992
  • This paper shows that the identified and unidentified components of surface roughness in NC turning lathe which can not be analyzed in time domain such as $R_{max},\;R_a$ can be isolated in frequency domain by FFT analyzer. By interfacing FFT analyzer with stylus surface roughness instrument, surface roughness on change of working condition, especially tool feed, such as 0.1, 0.15, 0.2, 0.25, 0.3(mm/rev) can be analyzed in frequency domain as follows. 1. By frequency analysis of surface roughness profile, the basic wave length of surface roughness can be obtained to isolate the identified and unidentified components of surface roughness. 2. With increase of tool feed, the unidentified components of surface roughness increase. 3. Since $R_{max}$, which can be obtained by stylus surface roughness is proportion to the output voltage of FFT analyzer, FFT analyzer also can be used to measure surface roughness in time domain such $R_a,\;R_{max}$.

  • PDF

Experimental Surface Roughness Estimation in Multi-Pass Horizontal Grinding Operations (다회가공 평면연삭작업에서 표면조도의 실험적 예측)

  • 최후곤;김재윤;여명구
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.2
    • /
    • pp.64-72
    • /
    • 2000
  • Surface roughness is one of the most important characteristics in machining processes. This study presents probabilistic models to estimate surface roughness experimentally in multi-pass horizontal surface grinding operations from three independent distributions such as the initial surface roughness distributions of workpiece, the distributions of the wheel radius, and the distributions of distances between major active grains. To specify the model characteristics from surface roughness measurements, either the probability satisfying a given surface roughness or the range of surface roughness satisfying a given probability have been estimated while grinding conditions are fixed. Finally, the relationship between grinding conditions satisfying surface roughness range under a given probability can be established.

  • PDF

Effect of surface roughness on laminar flow in a micro-channel by using lattice Boltzmann method (격자 볼츠만 방법을 이용한 미소채널 내에서의 층류 유동에 대한 표면 거칠기의 영향)

  • Shin, Myung-Seob;Yoon, Joon-Yong;Byun, Sung-Joon;Kim, Kak-Joong
    • 유체기계공업학회:학술대회논문집
    • /
    • /
    • pp.179-183
    • /
    • 2006
  • Surface roughness is present in most of the microfluidic devices due to the microfabrication techniques. This paper presents lattice Boltzmann method (LBM) results for laminar flow in a microchannel with surface roughness. The surface roughness is modeled by an array of rectangular modules placed on top and bottom side of a parallel-plate channel. In this study, LBGK D2Q9 code in lattice Boltzmann Method is used to simulate flow field for low Reynolds number in a micro-channel. The effects of relative surface roughness, roughness distribution, roughness size and the results are presented in the form of the product of friction factor and Reynolds number. Finally, a significant increase in Poiseuille number is detected as the surface roughness is considered, while the effect of roughness on the microflow field depends on the surface roughness.

  • PDF

Measuring System of Surface Roughness for On-The-Machine using Diffraction Light (회절광을 이용한 기상계측용 표면거칠기의 측정시스템)

  • 김성훈;이기용;강명창;김정석;김남경
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • /
    • pp.803-807
    • /
    • 2000
  • This paper deals wi th the establishment of the method of non-contact surface roughness measurement by developed system. One of the most Important factor of determinating quality of a produced manufacture is surface roughness The tendency of manufacturing method is changing from small amount manufactures / high-volume production to large amount manufactures / low volume production, and the study of reducing time for surface roughness measurement has been actively investigated The non-contact surface roughness method by using laser which is different from contact method has been only used to the polished surface, so new surface roughness measurement method was adopted by virtue of Fraunhofer diffraction in the periodic surface for on-the-machine. in this paper, we establish the method of non-contact surface roughness measurement which can reduce measuring time in the periodic surface

  • PDF

Effects of Cutting Parameters on Surface Roughness in Planing Using Taguchi Method (다구찌 실험 계획법을 활용한 평삭 가공에서의 표면 거칠기에 대한 절삭조건 영향 분석)

  • Seo, Dong-Hyun;Kwon, Ye-Pil;Kim, Young-Jae;Choi, Hwan-Jin;Jeon, Eun-chae
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.20 no.8
    • /
    • pp.93-98
    • /
    • 2021
  • The complex effects of the machining parameters make it is difficult to control and predict surface roughness. The theoretical surface roughness observed during mechanical machining with a round tool is determined by the tool radius and pitch. However, it was revealed that other parameters, such as the depth of cut and cutting speed, also affect surface roughness. This study adapted the Taguchi method, which can analyze the effects of cutting parameters quantitatively with an efficient number of experiments, to optimize the parameters for better surface roughness. Experiments were designed based on an orthogonal array, and the quantitative effects on the surface roughness were analyzed using the S/N ratio. The surface roughness was affected by all parameters, especially the tool radius. The optimum cutting parameter values obtained in this study showed better surface roughness than the other combinations of the parameters.

Evaluation of surface roughness of heat-polymerized denture base resin according to the polishing step (연마 과정에 따른 열중합 의치상 레진의 표면 거칠기 평가)

  • Hwang, Seong-Sig;Im, Yong-Woon;Kim, Si-Chul;Han, Min-Soo
    • Journal of Technologic Dentistry
    • /
    • v.37 no.4
    • /
    • pp.205-212
    • /
    • 2015
  • Purpose: The objective of this study was to compare the surface roughness according to polishing process in conventional laboratory techniques used for polishing three different acrylic denture base resins. Materials and methods: Specimen preparation and surface polishing procedures were conducted to manufacturer's recommendation with three heat-polymerized denture base resins. Surface roughness and gloss were measured by a contact type tester and a LED gloss checker using thickness 2 mm and diameter 10 mm. There were five specimens for each acrylic resin material and polishing procedures. Mean average surface roughness (Ra) values of each specimen group were analyzed using a one-way ANOVA analysis of variance and Scheffe's post hoc test. Surfaces after surface roughness and gloss testing according to each polishing process were evaluated under a stereoscopic microscope. Results: The highest mean average surface roughness was measured($Ra=2.43{\pm}0.47$) for surfaces finished with a denture tungsten carbide bur in Triplex. The lowest surface roughness values ($Ra=0.11{\pm}0.07$) were determined in Vertex polished with a lathe. In addition, all materials revealed that surface roughness determined highly in HP1 and HP2 than other procedures. All correlation between surface roughness and gloss showed highly with three heat-polymerized resins. Specially, topmost correlation revealed than other material in Triplex. Significant differences in mean average surface roughness were found between polishing process used high speed lathe and low speed hand-piece. Conclusion: Laboratory polishing used to high speed was found to produce the smoothest surface of heat-polymerized denture base acrylic resin. Therefore, we recommended that high polishing process need to get smooth surface.

Study on the effect of the surface rolling condition to the surface roughness (표면 Rolling시 작업조건이 표면조도에 미치는 영향)

  • 강명순;김희남
    • Journal of the korean Society of Automotive Engineers
    • /
    • v.8 no.3
    • /
    • pp.68-76
    • /
    • 1986
  • The surface rolling method which is one of the plastic deformation processes increases the surface roughness and hardness of materials. In this study, three NACHI6000 ZZ bearing were used for surface rolling tool on the mild steel and high carbon steel. The purpose of this study is to investigate the effects of rolling speed, feed rate and contact pressure on the surface roughness. The following results have been obtained with the mild steel and high carbon steel. 1. The roller finishing method has increased surface roughness from 2.4 .mu.m Ra at initial ground surface to 0.17 .mu.m Ra-0.4 .mu.m Ra. 2. The contact pressure has influenced greatly on the surface roughness. There is an optimal contact pressure. 3. As the rolling speed and the feed rate decrease, the surface roughness improves. 4. The optimal contact pressure for the good surface roughness of SS40 and STC 3 has been at 213 Kgf/Cm$^{2}$ and 220 Kgf/Cm$^{2}$ respectively.

  • PDF

Surface roughness prediction with a full factorial design in turning (완전요인계획에 의한 선삭가공시 표면거칠기 예측)

  • Yang, Seung-Han;Lee, Young-Moon;Bae, Byong-Jung
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.1 no.1
    • /
    • pp.133-140
    • /
    • 2002
  • The object of this paper is to predict the surface roughness using the experiment equation of surface roughness, which is developed with a full factorial design in turning. $3^3$ full factorial design has been used to study main and interaction effects of main cutting parameters such as cutting speed, feed rate, and depth of cut, on surface roughness. For prediction of surface roughness, the arithmetic average (Ra) is used, and stepwise regression has been used to check the significance of all effects of cutting parameters. Using the result of these, the experimental equation of surface roughness, which consists of significant effects of cutting parameters, has been developed. The coefficient of determination of this equation is 0.9908. And the prediction ability of this equation was verified by additional experiments. The result of that, the coefficient of determination is 0.9718.

  • PDF

A Study on Characteristics of Surface Roughness by Cutting Condition Variation in Face Milling (정면밀링가공시 절삭조건 변화에 표면거칠기 특성에 관한 연구)

  • 김성일
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • /
    • pp.248-253
    • /
    • 1997
  • The ideal surface roughness is obtained by tool geometry and feed rate in face milling. however actual surface roughness is affected by various factors such as cutting conditions. vibration and used tool. To improve the quality and productivity of the machining parts, lots of research on the evaluation of tool life and control of surface roughness has been required. Therefore, the width of flank wear, cutting force, and surface roughness are monitored to analyse the characteristics of surface roughness. This experimental investigation is mainly focused on the characteristics of surface roughness in multi-insert milling using TiN coated tool.

  • PDF

A Study on the Surface Roughness in Grinding Process by Frequency Analysis (평면연삭(平面硏削)에서 주파수(周波數) 분석(分析)에 의한 표면(表面) 거칠기 해석(解釋))

  • Kim, G.N.;Cheong, C.C.;Kim, K.S.
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.11 no.2
    • /
    • pp.32-41
    • /
    • 1991
  • This paper is to analyze the surface roughness in wet and dry surface grinding in which working conditions are table feed, cross feed and down feed. FFT analyzer is used to identify the surface roughness and the data of surface roughness are stored and displayed using an interfaced computer. In results, components affecting surface roughness exist within 200Hz with respect the conditions and methods of grinding operation. Also, with increase of table feed, cross feed and down feed, the value of surface roughness increases. Of them, cross feed has first influence on surface roughness. In dry, preciser surface can be obtained than one in wet.

  • PDF