• 제목, 요약, 키워드: Wear

검색결과 6,894건 처리시간 0.06초

무가압함침법으로 제조된 입자강화 금속복합재료의 마모특성 (Wear Characteristics of Particulate Reinforced Metal Matrix Composites Fabricated by Pressureless Metal Infiltration Process)

  • 김재동;정순억;김형진
    • 한국해양공학회:학술대회논문집
    • /
    • /
    • pp.379-384
    • /
    • 2002
  • The effect of size and volume fraction of ceramic particles with sliding velocity on the wear properties were investigated for the metal matrix composites fabricated by pressureless infiltration process. The particulate metal matrix composites exhibited about 5.5 - 6 times of excellent wear resistance compared with AC8A alloy at high sliding velocity, and as increasing the particle size and decreasing the volume fraction the wear resistance was improved. The wear resistance of metal matrix composites and AC8A alloy exhibited different aspects. Wear loss of AC8A alloy increased with sliding velocity linearly. whereas metal matrix composites indicated more wear loss than AC8A alloy at slow velocity region, however a transition point of wear loss was found at middle velocity region which show the minimum wear loss, and wear loss at high velocity region exhibited nearly same value with slow velocity region. In terms of wear mechanism, the metal matrix composites exhibited the abrasive wear at slow to high sliding velocity generally, however AC8A alloy showed abrasive wear at low sliding velocity and adhesive and melt wear at high sliding velocity.

  • PDF

SUS 304에 대한 Inconel 600의 Sliding 마모거동 (The Sliding Wear Behavior of Inconel 600 Mated with SUS 304)

  • 김훈;최종현;김준기;박기성;김승태;김선진
    • 한국재료학회지
    • /
    • v.11 no.10
    • /
    • pp.841-845
    • /
    • 2001
  • The steam generator tubes of power plant damaged by sliding wear due to flow-induced motion of foreign object. Amount of wear have been predicted by Achard's wear equation until now. However, there are large error and low reliability, because this equation regards wear coefficient(k) as constant. The sliding wears tests have been performed at room temperature to examine parameters of wear (wear distance, contact stress). The steam generator tube material for wear test is used Inconel 600 and foreign object material is used 304 austenite stainless steel. The sliding wear tests show that the amount of wear is not linearly proportional to the wear distance(for 374 austenite stainless steel). According to experimental result, wear coefficient is not constant k but function k(s) of wear distance. The newly modified wear predictive equation V=k(s)F have small error and high reliability.

  • PDF

무가압함침법으로 제조된 입자강화 금속복합재료의 마모특성 (Wear Characteristics of Particulate Reinforced Metal Matrix Composites Fabricated by a Pressureless Metal Infiltration Process)

  • 김재동;정순억;김형진
    • 한국해양공학회지
    • /
    • v.17 no.1
    • /
    • pp.55-60
    • /
    • 2003
  • The effect of size and volume fraction of ceramic particles, with sliding velocity on the wear properties were investigated for the metal matrix composites fabricated by the pressureless infiltration process. The metal matrix composites exhibited about 5.5 - 6 times the wear resistance compared with AC8A alloy at high sliding velocity, and by increasing the particle size and decreasing the volume fraction, the wear resistance was improved. The wear resistance of metal matrix composites and AC8A alloy exhibited different aspects. Wear loss of AC8A alloy increased with sliding velocity, linearly : whereas, metal matrix composites indicated more wear loss than AC8A alloy at the slow velocity region. However, a transition point of wear loss was found at the middle velocity region, which shows the minimum wear loss. Further, wear loss at the high velocity region exhibited nearly the same value as the slow velocity region. In terms of wear mechanism, the metal matrix composites generally exhibited abrasive wear at slow to high sliding velocity; however, AC8A alloy showed abrasive wear at low sliding velocity and adhesive and melt wear at high sliding velocity.

입방정계 순 금속 Fe, Cu의 미끄럼 마멸 거동 (Sliding Wear Behavior of Pure Metal, Fe and Cu Having a Cubic Crystal System)

  • 이슬기;김용석
    • 소성가공
    • /
    • v.19 no.6
    • /
    • pp.357-362
    • /
    • 2010
  • Dry sliding wear behavior of pure Fe and Cu which have BCC and FCC crystal structure, respectively, was investigated. The wear characteristics of the pure metals with different crystal structure were compared. Dry sliding wear tests were carried out using a pin-on-disk wear tester at various loads under the constant sliding speed condition of 0.15 m/s against a silica ball at room temperature. Sliding distance was fixed as 600 m for all wear tests. Wear rate of a specimen was calculated by dividing the weight loss of the specimen after the test by the specific gravity and sliding distance. Worn surfaces and wear debris were analyzed by SEM. The wear of both pure Fe and Cu proceeded with surface deformation, resulting in similar wear rates despite of their structure difference under the current test conditions. Wear rates of both metals were low if the surface deformation due to wear forms thick surface-deformation layer that is strain hardened beneath the wearing surface. The pure Cu specimens showed a lot of oxides on the worn surface when tested at low loads less than 5 N, which resulted in very low wear rate.

THEORETICAL ANALYSIS FOR STUDYING THE FRETTING WEAR PROBLEM OF STEAM GENERATOR TUBES IN A NUCLEAR POWER PLANT

  • LEE CROON YEOL;CHAI YOUNG SUCK;BAE JOON WOO
    • Nuclear Engineering and Technology
    • /
    • v.37 no.2
    • /
    • pp.201-206
    • /
    • 2005
  • Fretting, which is a special type of wear, is defined as small amplitude relative motion along the contacting interface between two materials. The structural integrity of steam generators in nuclear power plants is very much dependent upon the fretting wear characteristics of Inconel 690 U-tubes. In this study, a finite element model that can simulate fretting wear on the secondary side of the steam generator was developed and used for a quantitative investigation of the fretting wear phenomenon. Finite element modeling of elastic contact wear problems was performed to demonstrate the feasibility of applying the finite element method to fretting wear problems. The elastic beam problem, with existing solutions, is treated as a numerical example. By introducing a control parameter s, which scaled up the wear constant and scaled down the cycle numbers, the algorithm was shown to greatly reduce the time required for the analysis. The work rate model was adopted in the wear model. In the three-dimensional finite element analysis, a quarterly symmetric model was used to simulate cross tubes contacting at right angles. The wear constant of Inconel 690 in the work rate model was taken as $K=26.7{\times}10^{-15}\;Pa^{-1}$ from experimental data obtained using a fretting wear test rig with a piezoelectric actuator. The analyses revealed donut-shaped wear along the contacting boundary, which is a typical feature of fretting wear.

수복재료에 대합되는 의치용 레진치의 마모저항성 비교 (COMPARISON OF WEAR RESISTANCE AMONG RESIN DENTURE TEETH OPPOSING VAR10US RESTORATIVE MATERIALS)

  • 이철영;정문규
    • 대한치과보철학회지
    • /
    • v.37 no.3
    • /
    • pp.313-327
    • /
    • 1999
  • The aim of this study was to compare wear resistance of resin denture teeth opposing various restorative materials. The wear resistance of conventional acrylic resin teeth(Trubyte Biotone) and three high-strength resin teeth(Bioform IPN, Endura, SR-Orthosit-PE) opposing different restorative materials(gold alloys, dental porcelain, composite resin) was compared. Wear tests were conducted with a sliding-induced wear testing apparatus which applied 100,000 strokes to the specimen in a mesio-distal direction under conditions of 100 stroke/min and constant loading of 1Kgf/tooth. Wear resistance of the resin denture teeth was evaluated by the following criteria : 1) wear depth, 2) weight loss, and 3) SEM observation. Results were as follows. 1. When opposed to gold alloys and composite resin, high-strength resin teeth showed superior wear resistance compared to acrylic resin teeth. But, in cases opposing dental porcelain, differences between the wear of the high-strength and acrylic resin teeth were not statistically significant (p<0.05). 2. When comparing wear resistance among high-strength resin teeth, opposing gold alloys, Endura was slightly more resistant and while in cases opposing dental porcelain, SR-Orthosit-PE was showed to be slightly resistant(p<0.05). 3. The wear of high-strength resin teeth was greater by 5 to 7 times when opposing porcelain and 2 to 3 times when opposing composite resin compared to gold alloys(p<0.05). 4. SEM observations of the wear surface showed that wear of resin teeth opposing gold alloys is a fatigue type of wear and wear of resin teeth opposing dental porcelain is fatigue and abrasion type of wear. Trubyte Biotone showed more severe fatigue type of wear than high-strength resin teeth. In conclusion, the use of dental porcelain should seriously be considered as restorative material in cases opposing resin denture teeth and improvement seems to be needed on resin teeth in the areas of wear resistance.

  • PDF

X선회절에 의한 미끄럼접촉시 발생하는 마모과정의 해석(제1보 : 저경도강의 적용) (Analysis of Wear Proccess in Sliding Contact by X-ray Diffraction)

  • 이한영
    • 한국윤활학회:학술대회논문집
    • /
    • /
    • pp.19-24
    • /
    • 1999
  • Understanding of wear mode and prediction of wear rate of parts in sliding contact are very important in field of meterial design relating with wear resistant. This paper has been undertaken to analyze the possibility of elucidation of wear mode and prediction of wear rate for annealed steel in sliding contact using the X-ray diffraction. The sliding wear test with various velocities using pin-on-disc machine and the X-ray diffraction test on the worn surface have been carried out. The results have been shown that the magnitude of residual stress and half-value breadth on the worn surface have a good correlation with wear mode. The difference between before and after test of half-value breadth on worn surface has been shown to be exponential relation with wear rate in the same wear mode.

  • PDF

반복 미끄럼 접촉에 의한 표면층의 경화에 대한 연구 (A Study on the surface hardening by repeated sliding contact)

  • 박준목;김석삼
    • 한국윤활학회:학술대회논문집
    • /
    • /
    • pp.80-88
    • /
    • 1997
  • Repeated sliding contact wear test was performed with copper specimens to obtain the relationship between wear and surface hardening. Wear surface and wear track section were observed by optical microscopy. Wear volume and micro-vikers hardness of sublayer below wear surface were obtained. These results suggested that wear mechanism depended on contact load than sliding velocity. Therefore wear mechanism was abrasive wear within critical contact load and adhesive wear over critical contact load. Wear rate increased with contact load, sliding distance but decreased with sliding velocity. Surface hardening increased with sliding velocity and sliding distance but decreased with contact load.

  • PDF

경도의 차이에 따른 재료들의 비윤활 미끄럼 마모에 대한 연구 (A Study of Unlubricated Sliding wear of materials as hardness difference)

  • 김정현
    • 한국산업융합학회 논문집
    • /
    • v.7 no.4
    • /
    • pp.369-376
    • /
    • 2004
  • It is shown that the rate of wear can be related to on 'index of wear intensity'. Since both upper and lower specimens have used the same hardness values, equivalent hardness of 'index of wear intensity' used the mean hardness value of specimens. This index is derived from the external variables of load, sliding speed and the hardness of the sliding pairs. 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. Using experimental data, we figured the relationship between wea rate and index of wear intensity. The result had been derived a newly wear equation in disc on disc wear system.

  • PDF

Study on Quantitative Analysis of Wear Debris for Surface Modification Layers Ti(C,N) with Piston Ring on Diesel Engine Oil

  • Choi, Nag-Jung;Youn, Suk-Bum;Kim, Min-Soo
    • 한국마린엔지니어링학회지
    • /
    • v.33 no.7
    • /
    • pp.1044-1051
    • /
    • 2009
  • During contact between surfaces, there is wear and the generation of wear. The particles contained in the lubricating oil carry detailed and important monitoring information about the condition of the machine. Therefore, this paper was undertaken for the Ferrography system of wear debris generated from a lubricated moving machine surface. The lubricating wear test was performed under different experimental conditions using the Falex wear test of the Pin and V-Block types by Ti(C,N) coated. It was shown from the test results that wear particle concentration(WPC), wear severity index(Is) and size distribution have come out all higher with increases in sliding friction time. With the Ferrogram thin leaf wear debris as well as ball and plate type wear particles were observed.