• 제목, 요약, 키워드: Wear

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증기발생기 튜브재질의 미끄럼 마멸 및 프레팅 마멸 특성 (Sliding Wear and Fretting Wear of Steam Generator Tube Materials)

  • 김동구;조정우;이영제
    • Tribology and Lubricants
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    • v.17 no.5
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    • pp.380-385
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    • 2001
  • In nuclear power steam generators, high flow rates can induce vibration of the tubes resulting in fretting wear damage due to contacts between the tubes and their supports. In this paper the fretting wear tests and the sliding wear tests were performed using the steam generator tube materials of Inconel 600 and 690 against STS 304. Sliding tests with the pin-on-disk type tribometer were done under various applied loads and sliding speeds at air environment. Fretting tests were done under various vibrating amplitudes and applied normal loads. From the results of sliding and fretting wear tests, the wear of Inconel 600 and 690 can be predictable using the work rate model. Depending on normal loads and vibrating amplitudes, distinctively different wear mechanisms and often drastically different wear rates can occur. It was found the results that the wear coefficients for Inconel 600 and 690 were 262.3$\times$10$\^$-15/Pa$\^$-1/ and 209.2$\times$10$\^$-15/Pa$\^$-1/, respectively. This study shows that Inconel 690 can provide much better wear resistance than Inconel 600 in air.

법랑질에 의한 수종의 간접복합레진의 마모에 관한 연구 (AN IN-VITRO WEAR STUDY OF INDIRECT COMPOSITE RESINS AGAINST HUMAN ENAMEL)

  • 이현정;전영찬;정창모;정희찬
    • 대한치과보철학회지
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    • v.45 no.5
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    • pp.611-620
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    • 2007
  • Statement of problem: Second-generation indirect composite resins have been improved flexural strength, compressive strength, hydrolytic degradation resistance, wear resistance compared to first-generation indirect composite resins, but there are still some problems as hydrolysis and low wear resistance. Some manufacturers claim that wear resistance of their materials has been improved, but little independent study has been published on wear properties of these materials and the properties specified in the advertising materials are largely derived from in-house or contracted testing. Purpose: This study was to evaluate the wear of indirect composite resins (SR Adore, Sinfony, Tescera ATL) and gold alloy against the human enamel. Material and method: Extracted human incisors and premolars were sectioned to $2{\times}2{\times}2mm$ cube and embedded in the clear resin and formed conical shaped antagonist to fit the jig of pin-on-disk tribometer. Total 20 antagonists were stored in distilled water. Five disk samples, 24mm in diameter and 1.5mm thick, were made for each of three groups of indirect composite resins and gold alloy group, and polished to #2,000 SiC paper on auto-polishing machine. Disk specimens were tested for wear against enamel antagonists. Wear test were conducted in distilled water using a pin-on-disk tribometer under condition (sliding speed 200rpm contact load 24N, sliding distance 160m). The wear of the enamel was determined by weighing the enamel antagonist before and after test, and the weight was converted to volumes by average density. The wear tracks were analyzed by scanning electron microscopy and surface profilometer to elucidate the wear mechanisms. Statistical analysis of the enamel wear volume, wear track depth and wear tract width of disk specimens were accomplished with one-way ANOVA and the means were compared for significant differences with Scheffe's test. Results: 1. The enamel wear was most in gold alloy, but there were no statistically significant differences among all the groups (P>.05). 2. In indirect composite resin groups, the group to make the most shallow depth of wear tract was Sinfony, followed by Tescera ATL, SR Adoro (P<.05). Gold alloy was shallower than Sinfony, but there was no statistically significant difference between Sinfony and gold alloy (P>.05). 3. The width of wear tract of SR Adore was larger than the other groups (P<.05), and there were no statistically significant differences among the other groups (P>.05). 4. SEM analysis revealed that Sinfony and gold alloy showed less wear scars after test, Tescera ATL showed more wear scars and SR Adore showed the most. Conclusion: Within the limits of this study, Sinfony and gold alloy showed the least wear rates and showed similar wear patterns.

직장여성을 위한 이지 캐주얼 웨어 디자인 개발 (The Design Development of Easy Casual Wear for Career Women)

  • 변미연;이인성
    • 한국의류학회지
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    • v.30 no.8
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    • pp.1301-1311
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    • 2006
  • This study rearranged a concept of Friday wear considered as casual wear by searching social background through analysis of literature study and photo materials and classifying by characteristics of casual wear. It investigated growing changes of casual wear and the progress of changes casual brands through a market survey based on departments in Seoul. And then, it examined characteristics of a design and the critical point of easy casual selecting GIORDANO, TBJ and NII of three easy casual brands. Conclusions of the study are as follows: Firstly, present casual wear showed subdivision of casual wear as abundant grouping vocabularies appeared contrary to the past. Secondly, easy casual wear has continuously increased by results of investigating departments in Seoul on the progress of changing easy casual wear brand including the concept of Friday wear. Thirdly, if a main target sets the early 20s, women workers in their 20's and 30's are likely to be reluctant to wear it according to results of investigating designs and characteristics based on GIORDANO, TBJ and NII of existing three easy casual brands through the market survey. Also, it was verified that most of these brands have no a luxurious image because they adhere to middle-low price. Fourthly, it improved problems of easy casual through developing designs of easy casual wear. Easy casual wear supplementing weak these points of easy casual wear was evaluated as suitable clothes for workers to wear in on and off their own time in Friday.

등산동기가 등산복 추구혜택 및 등산복 착용행동에 미치는 영향 (The Effects of Mountain Climbing Motivation and Mountain Climbing Wear Benefits Sought on Clothing Usage Behavior)

  • 안서영;윤승원;이미아;고애란
    • 한국의류학회지
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    • v.37 no.4
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    • pp.565-576
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    • 2013
  • This study investigated 1) the effects of mountain climbing motivation on the desired mountain climbing wear benefits, and 2) the desired effects of mountain climbing wear benefits on clothing usage behavior. Data were collected via a questionnaire administered to 498 consumers who make at least one mountain climbing wear purchase for personal use. All items were evaluated on a 5-point Likert scale, and SPSS 20.0 and Amos 7.0 were used for data analysis. Confirmatory factor analysis for the research variables were performed and three factors of mountain climbing motivation (social interaction, health improvement, and mental rejuvenation), four factors of mountain climbing wear benefits sought (ostentation, ideal healthy figure, conformity, and functions), and two factors regarding clothing usage behavior (sportswear usage and daily wear usage) were identified. The results from the model test were as follows: 1) Mountain climbing motivation was found to vary depending on the mountain climbing wear benefits sought. Social interaction had a positive effect on all 4 factors of mountain climbing wear benefits sought. Health improvement was the only motivating factor for consumers who sought the benefit of functions; however, the functions benefit was not found to be a consideration for consumers who climbed for mental rejuvenation. 2) Mountain climbing wear usage was affected by mountain climbing wear benefits sought. The benefits for conformity and functions had a positive effect on sportswear usage and daily wear usage; however, the ideal healthy figure only affected daily wear usage. The twofold usage of mountain climbing wear reflects a cultural trend toward the usage of mountain climbing wear as daily wear; however, consumers show this twofold usage to conform successfully to mainstream society and not to pursue the ideal healthy figure.

디젤엔진용 실린더 라이너 소재의 고온 마모특성 (Wear Characteristics of Cylinder-Liner Materials for Diesel Engine at Elevated Temperature)

  • 김진열;김재훈;오광근;이승학;장준용
    • 대한기계학회논문집A
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    • v.39 no.11
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    • pp.1131-1136
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    • 2015
  • 선박 디젤엔진용 실린더 라이너는 피스톤 링과 지속적인 왕복운동을 통해 마모가 발생한다. 마모는 디젤엔진의 성능을 저하시키고, 사용 수명을 단축시킨다. 본 논문은 선박 디젤엔진용 실린더 라이너의 GT 금속 및 기존 금속에 대하여 마모특성을 평가하였다. 마모시험은 상온, $175^{\circ}C$, $325^{\circ}C$의 온도조건과 10 N, 30 N, 50 N 의 하중조건에서 수행되었으며, 마모량, 비마마율 및 마찰계수를 평가하였다. 또한 각 조건에 대한 마모메커니즘을 분석하기 위해서 SEM 분석을 수행하였다. 두 금속 공히, 상온에서 연삭 및 응착마모가 진행되었고, 고온에서 부식마모가 발견되었다. GT 금속은 기존 금속 대비 모든 온도 범위에서 마모량 및 비마모율이 작고 마모특성이 더 우수하다.

어린이집 활동복 개발 연구 -아동 민속놀이 캐릭터를 활용하여- (A Study for the Improvement of the Nursery Active-wear Uniform -By Characters based on Children's Folklore Plays-)

  • 문명옥;이진숙;엄정옥
    • 한국의류산업학회지
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    • v.15 no.3
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    • pp.347-357
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    • 2013
  • The nursery active-wear uniform designs of Internet shopping malls are simple and similar; however, the latest children's wear trends (mostly composed of training jumpers and pants) do not reflect these qualities. Children's folklore plays (widely used in child education) have an instructive value for the emotional and intellectual development of a child. Nursery active-wear uniform designs applied to children's folklore's plays could be positive for the emotional development and specialized cultural education of children. We designed three nursery active-wear uniforms with three different design concepts (casual, semi-formal and sporty) regardless of sex. The main color of the three nursery active-wear uniforms was yellow. We used three different chroma and values of yellow through three design concepts: Design I of a nursery active-wear uniform (a training suit style with a good activity), Design II of a nursery active-wear uniform (a semi suit style), and Design III of a nursery active-wear uniform (a sportswear style that reflected a sport wear trend). We expressed children's folklore plays in the pattern of a nursery active-wear uniform. The pattern was characterized as a pair of bears flying kites. This pattern was utilized in three nursery active-wear uniforms with the logo and name of the nursery. We modified the designs of active-wear nursery uniforms based on an evaluation of 33 special panels. We made three nursery active-wear uniforms for five-year olds.

노년기 남성의 의복디자인 선호도 및 치수적합에 대한 만족도에 관한 연구 (A Study of Clothing Design Preference & Satisfaction with the Fit of Ready-to-Wear Clothing for Older Men)

  • 서미아;이선희
    • 복식문화연구
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    • v.8 no.6
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    • pp.864-870
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    • 2000
  • The purpose of this study were to investigate clothing design preference (style, color, fabric print, kinds of fabrics) & satisfaction with the fit of ready-to-wear clothing for older Men. For this study, the questionnaires were administered to 650 older men in seoul from June to August, 1998. Employing a sample of 504 data were analyzed by mean, frequency and percent. With respect to clothing design preference, they prefer suit the style of outdoor clothing on going-out. On distinguish clothing into formal wear & casual wear, the color preference due to seasons has difference in spring clothing. Regarding the degree of fabric pattern preference, nonpattern single color fabric has occupied in formal wear, pattern in casual wear. Regarding the degree of fabric preference, they take a serious view of shape preservation in formal wear, utility (washing, sweat absorption) in causal wear. Suit has the lowest satisfaction in the fit of ready-to-wear clothing. Sleeve length the lowest in the degree of satisfaction for each part.

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냉간 단조 금형의 마멸 감소를 위한 예비성형체 설계방법 (Methodology of Perform Design for Reducing Tool Wear in Cold Forging)

  • 이진호;고대철;김태형;김병민;최재찬
    • 한국소성가공학회:학술대회논문집
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    • pp.164-167
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    • 1997
  • The die wear is one of the main factors affecting die accuracy and tool lifetime. It is desired to reduce die wear by developing simulation method to predict wear based on process parameters, and then optimize the process. Therefore, this paper describes disign methodology of preform for minimizing wear of finisher die in multi-stage cold forging processes. The finite element method is combined with the routine of wear prediction and the cold forging processes. The finite element method is combined with the routine of wear prediction and the cold forging process is analyzed. In order to obtain preform to minimize die wear, the FPS algorithm is applied and the optimal preform shape is found from iterative deformation analysis and wear calculation.

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구름접촉시 세라믹의 거시적 마모특성 (Macroscopic Wear Characteristics of Ceramics under the Rolling Contact)

  • Kim, Seock-Sam;Koto, Kohji;Hokkirigawa, Kzauo
    • Tribology and Lubricants
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    • v.5 no.1
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    • pp.28-35
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    • 1989
  • The wear tests of ceramic materials in dry rolling contact were carried out at room temperature to investigate their macroscopic wear characteristics. Both point contact and line cootact were adapted in the wear tests of them. Ceramic materials used in these tests were silicon nitride, silicon carbide, cermet of TiN and TiC, titania, and alumina. The wear test of the bearing steel was carried out to compare to the wear test results of the ceramic materials. The results showed that the wear rate of silicon nitride was smaller than any other ceramic materials and bearing steel. In the steady wear, the wear volume of ceramic materials increases linearly with the rolling distance. It was also found from the experimental results that fracture toughness and surface roughness dominate the wear process of ceramic materials in dry rolling contact.

Shape Study of Wear Debris in Oil-Lubricated System with Neural Network

  • Park, Heung-Sik;Seo, Young-Baek;Cho, Yon-Sang
    • KSTLE International Journal
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    • v.2 no.1
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    • pp.65-70
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    • 2001
  • The wear debris is fall off the moving surfaces in oil-lubricated systems and its morphology is directly related to the damage and failure to the interacting surfaces. The morphology of the wear particles are therefore directly indicative of wear processes occurring in tribological system. The computer image processing and artificial neural network was applied to shape study and identify wear debris generated from the lubricated moving system. In order to describe the characteristics of various wear particles, four representative parameter (50% volumetric diameter, aspect, roundness and reflectivity) from computer image analysis for groups of randomly sampled wear particles, are used as inputs to the network and learned the friction condition of five values (material 3, applied load 1, sliding distance 1). It is shown that identification results depend on the ranges of these shape parameters learned. The three kinds of the wear debris had a different pattern characteristics and recognized the friction condition and materials very well by neural network. We discuss how these approach can be applied to condition diagnosis of the oil-lubricated tribological system.

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