• 제목, 요약, 키워드: Wear

검색결과 6,894건 처리시간 0.061초

Wear Behaviors of Ceramics TIN, TIC and TICN with Arc Ion Plating

  • Oh, Seong-Mo;Rhee, Bong-Goo;Jeong, Bong-Soo
    • Journal of Mechanical Science and Technology
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    • v.17 no.12
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    • pp.1904-1911
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    • 2003
  • In order to determine the wear properties of AIP (Arc Ion Plating) deposition, wear process was evaluated by using a Falex test machine. Also, in order to determine the effects of coating material on the wear process, TiC, TiN, and TiCN coatings of thickness about 5 $\mu\textrm{m}$∼6 $\mu\textrm{m}$ coated by Arc ion plating deposition method were tested. The wear property was determined under a dry sliding condition as a function of the applied load, sliding distance, sliding velocity and temperature. The results show that when wear of the coating-layer occurred, specific wear amount increased with the wear rate. At initial state, the wear rate rapidly increased, but it gradually reduced as the velocity increased. Also, when raising the temperature, the wear rate increased in the order of TiCN, TiN and TiC due to the frictional heat.

디스크 언 디스크 시스템에서 경도에 따른 건식 마모거동 (A dry wear behavior as hardness difffrence in a dual disc on disc sliding wear tests)

  • 김정현
    • 한국공작기계학회논문집
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    • v.13 no.5
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    • pp.16-23
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    • 2004
  • The wear behavior as the hardness of the sliding elements on the dry wear has been investigated using a disc on disc configuration. The materials of the specimens are used as ten kinds along their hardness. In this study, both upper and lower specimens have been used the same materials. Using experimental data, we figured the relationship between wear coefficient and friction coefficient, and the relationship between wear coefficient and friction temperature. Also we combined friction temperature and friction coefficient instead of wear coefficient. We substituted this into wear equation of Archard. The result had been derived a newly wear equation in disc on disc wear system.

부식 환경에서 SUS304 스테인레스 강의 마모 거동 (Wear Behavior of SUS304 Stainless Steels in Corrosive Environment)

  • 이광진;윤상돈;구영필;김형자
    • Tribology and Lubricants
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    • v.20 no.2
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    • pp.91-96
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    • 2004
  • Wear behavior of self-mated stainless steels in NaCl solution has been investigated. The experiment was done in the corrosive liquid of which NaCl concentration of $0\~3\%$ and temperature of $15\~90^{\circ}C$. Two kinds of wear type were observed: one is 'severe wear' type which shows gradually increasing wear volume with increasing sliding distances, the other is 'mild wear' type which shows change of wear rate from high value to low at transition distance. The specific wear rate in severe wear type was not sensitive to the liquid temperature and concentration of NaCl but stable at value of $1\times10^{-3}\;mm^3$ approximately.

기상 요인이 의류제품 매출에 미치는 영향분석 -백화점의 의류매출을 중심으로- (The Effects of Meteorological factors on Sales of Apparel Products - focused on apparel sales in the department store-)

  • 장은영;이선재
    • 복식
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    • v.52 no.2
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    • pp.139-150
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    • 2002
  • The purpose of this study was to explore the effects of meteorological factors on sales of apparel products. Basic fiat came out daily meteorological data and sales data of apparel products in department store from 1998 to 2000. Four factors(the average temperature, rainfall, wind velocity, sunshine duration) from the nine meteorological factors were selected and were collected with Korea Meteorological Administration. Sales data were collected with business strategy department of H (department store in Seoul. The sales data were divided into six classifications, which are woman's wear, men's wear, children's wear, golf wear, sports wear, and inner wear. The results of this study were as follows: 1) Sales of apparel products were significantly correlated with the average temperature, rainfall, wind velocity, sunshine duration. Among the meteorological factors, temperature turned out to be the most influential in apparel sales and then the amount of rainfall, sunshine duration affected sales according to apparel classifications differently. 2) There were some differences among the apparel classifications in the effect of meteorological factors on the sales of apparel. In the spring. the higher the temperature was, the higher the sales of women's wear and golf wear were, but the lower the sales of children's wear, sports wear and inner wear were. In the summer, The higher the amount of rainfall was, the lower the sales of all the apparel classification were. The higher the temperature was, the higher the sales of sports wear were. In the fall, the lower the temperature was, the higher the sales of all the apparel classification except snorts wear were. In the winter, the meteorological factors had little effect on the sales of women's wear, men's wear and children's wear. The higher the temperature was, the higher the sales of golf wear were. The lower the temperature was, the higher the sales of sports wear were.

A Study on Wear and Wear Mechanism of Exhaust Valve and Seat Insert Depending on Different Speeds Using a Simulator

  • Hong, Jae-Soo;Chun, Keyoung-Jin;Youn, Young-Han
    • Journal of Mechanical Science and Technology
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    • v.20 no.12
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    • pp.2052-2060
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    • 2006
  • The wear of engine valve and seat insert is one of the most important factors which affect engine performance. Because of higher demands on performance and the increasing use of alternative fuel, engine valve and seat insert are challenged with greater wear problems than in the past. In order to solve the above problems, a simulator was developed to be able to generate and control high temperatures and various speeds during motion. The wear simulator is considered to be a valid simulation of the engine valve and seat insert wear process with various speeds during engine activity. This work focuses on the different degrees of wear at three different singular test speeds (10 Hz, 25 Hz & multi-Hz). For this study, the temperature of the outer surface of the seat insert was controlled at 350$^{\circ}C$, and the test load was 1960 N. The test cycle number was $6.0{\times}10^6$. The mean ($\pm$standard error) wear depth of the valve at 10 Hz and 25 Hz was 45.1 ($\pm$3.7)$\mu$m and 81.7 ($\pm$2.5)$\mu$m, respectively. The mean wear depth of the seat insert at 10 Hz and 25 Hz was 52.7 ($\pm$3.9)$\mu$m and 91.2 ($\pm$2.7)$\mu$m, respectively. In the case of multi-Hz it was 70.7 ($\pm$2.4)$\mu$m and 77.4 ($\pm$3.8)$\mu$m, respectively. It was found that higher speed (25 Hz) cause a greater degree of wear than lower speed (10 Hz) under identical test condition (temperature, valve displacement, cycle number and test load). In the wear mechanisms of valves, adhesive wear, shear strain and abrasive wear could be observed. Also, in the wear mechanisms of seat inserts, adhesive wear, surface fatigue wear and abrasive wear could be observed.

여름용 잠옷착용실태와 구매행동에 관한 연구-충청지역 도시를 중심으로- (A Study on Use and Purchase Behavior of Sleeping wear for Summer in Chungchong area.)

  • 권수애;김은영;최종명;이은경
    • 한국의류학회지
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    • v.24 no.6
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    • pp.838-849
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    • 2000
  • The purpose of this study was to investigate use and purchase behavior of sleeping wear for summer. Subjects in this study were composed of 591 males and females aged from twenties to fifties, living in Taejon and Chongju. For data analysis, descriptive analysis, $\chi$$^2$-test, t-test, ANOVA, and factor analysis were used. The results are as follows. First, subjects used sleeping wear(a night gown and pajamas), and home wear(T-shirts and sweat suit with zippered top) with similar rates. The subjects, who are females, married, older and have professional jobs, owned sleeping wear such as a night gown and pajamas more than home wear. Also, the mean of using pajamas was the highest, and they were satisfied with them more than others who didn't wear them. Second, one-third of consumers purchased sleeping wear once a year in a specialty store. Consumers mainly searched for information regarding sleeping wear in the display section. Most consumers weren't influenced by others when they made their purchases. When consumers decided to purchase a product, they considered six criteria such as fabric/management, wearing/fitness, esthetic, service, symbolic status, and economic for evaluating. Among them, the factor wearing/fitness was considered the most important. These results imply that consumers would be conscious of sleeping wear even though sleeping wear and home wear are used interchangeably. In addition, consumer behavior concerning sleeping wear is different from their characteristics such as sex, age, occupation, the level of education, and marital state. Therefore, the markets with sleeping wear would be able to be segmented based on consumers’characteristics. Also, marketers should focus on distribution channels to reform the markets of sleeping wear, that is, they may offer products in specialty stores. Additionally, market managers would be able to concentrate on visual merchandising in stores in order to increase brand awareness and market share.

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대학생의 칫솔 마모도 평가 및 관련요인 분석 (Evaluation of Wear Index of Toothbrushes Used by University Students and Analysis of Related Factors)

  • 김선주
    • 한국콘텐츠학회논문지
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    • v.16 no.2
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    • pp.609-617
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    • 2016
  • 본 연구는 대학생들이 사용하고 있는 칫솔의 마모도와 마모율을 평가하고 관련요인을 파악하여 대학생 구강보건교육 자료로 활용하고자 하는데 목적이 있다. 2015년 3월 16일부터 4월 10일까지 573개의 칫솔을 수거한 뒤 칫솔 마모도를 평가하여 다음과 같은 결과를 얻었다. 칫솔 마모도는 조사 대상 칫솔 중 46.9%가 0.400 이상의 마모도를 보였고, 평균 마모도는 $0.403{\pm}0.20$로 조사되어, 전체적으로 높은 칫솔 마모도를 보였다. 칫솔 마모율은 1점과 2점이 차지하는 비율이 70.4%였으며, 평균 마모율은 $1.620{\pm}0.74$로 나타나 전체적으로 높은 칫솔 마모율을 보였다. 성별에 따른 칫솔 마모도 및 마모율은 남학생이 여학생보다 높았으며, 칫솔교체주기가 길수록 칫솔 마모도와 마모율 모두 유의하게 높았다. 대학생들의 칫솔교체 주기 및 칫솔 관리가 적절히 이루어질 수 있도록 올바른 칫솔관리에 대한 효율적인 구강보건교육 방안을 마련하는 것이 필요하다.

업셋팅 금형의 마모 실험 및 해석 (Experimental and Analytical Study on the Die Wear during the Upsetting Processes)

  • 박종남;김태형;강범수;이상용;이정환
    • 한국소성가공학회:학술대회논문집
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    • pp.122-130
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    • 1996
  • During the cold forming, due to high working pressure acting on the die surface, failure mechanics must be considered before die design. One of the main reasons of die failure in industrial application of metal forming technologies is wear. Die wear affects the tolerances of formed parts, metal flow and costs of process etc. The only way to control these failures is to develop methods which allow prediction of die wear and costs of process etc. The only way to control these failures is to develop methods which allow prediction of die wear and which are suited to be used in the design state in order to optimize the process. In this paper, the wear experiments to abtain the wear coefficients and the upsetting processes was accomplished to observe the wear phenomenon during the cold forming process. The analysis of upsetting processes was accomplished to observe the wear phenomenon during the cold forming process. The analysis of upsetting processes was accomplished by the rigid-plastic finite element method. The result from the deformation analysis was used to analyse the die wear during the processes and the predicted die wear profiles were compared with the measured die wear profiles.

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이온질화 처리강의 마모현상 분석에 관한 연구 (Study on the Analysis of Wear Phenomena of Ion-Nitrided Steel)

  • 조규식
    • Tribology and Lubricants
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    • v.13 no.1
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    • pp.42-52
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    • 1997
  • This paper deals with wear characteristics of ion-nitrided metal theoretically and experimentally in order to analysis of wear phenomena. Wear tests show that compound layer of ion-nitrided metal reduces wear rate when the applied wear load is mall. However, as th load becomes large, the existence of compound layer tends to increase wear rate. The residual stress at the surface of ion-nitrided metal is measured, and the internal stress distribution is calculated when the normal and tangential forces are applied to the surface of metal. Compressive residual stress is largeest at the compound layer, and decreases as the depth from the surface increases. Calculation shows that the maximum stress exists at a certain depth from the surface when normal and tangential force are applied, and that the larger the wear load is the deeper the location of maximum stress becomes. In the analysis, it is found that under small applied wear load the critical depth, where voids and cracks may be created and propagated, is located at the compound layer, as the adhesive wear, where hardness is an important factor, is created the existence of compound layer reduces the amount of wear. When the load becomes large the critical depth is located below the compound layer, and delamination, which may be explained by surface deformation, crack nucleation and propagation, is created, and the existence of compound layer increases wear rate.

Cold Data Identification using Raw Bit Error Rate in Wear Leveling for NAND Flash Memory

  • Hwang, Sang-Ho;Kwak, Jong Wook;Park, Chang-Hyeon
    • 한국컴퓨터정보학회논문지
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    • v.20 no.12
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    • pp.1-8
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    • 2015
  • Wear leveling techniques have been studied to prolong the lifetime of NAND flash memory. Most of studies have used Program/Erase(P/E) cycles as wear index for wear leveling. Unfortunately, P/E cycles could not predict the real lifetime of NAND flash blocks. Therefore, these algorithms have the limited performance from prolonging the lifetime when applied to the SSD. In order to apply the real lifetime, wear leveling algorithms, which use raw Bit Error Rate(rBER) as wear index, have been studied in recent years. In this paper, we propose CrEWL(Cold data identification using raw Bit error rate in Wear Leveling), which uses rBER as wear index to apply to the real lifetime. The proposed wear leveling reduces an overhead of garbage collections by using HBSQ(Hot Block Sequence Queue) which identifies hot data. In order to reduce overhead of wear leveling, CrEWL does not perform wear leveling until rBER of the some blocks reaches a threshold value. We evaluate CrEWL in comparison with the previous studies under the traces having the different Hot/Cold rate, and the experimental results show that our wear leveling technique can reduce the overhead up to 41% and prolong the lifetime up to 72% compared with previous wear leveling techniques.