• 제목/요약/키워드: X-ray diffraction technique

검색결과 466건 처리시간 0.023초

구름접촉을 하는 분말고속도공구강의 X선을 이용한 표면성상해석 (Analysis of Rolling Contact Surface on PM-High Speed Steel by X-ray Diffraction)

  • 이한영;김용진;배종수
    • Tribology and Lubricants
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    • 제19권1호
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    • pp.1-8
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    • 2003
  • Recently, PM-high speed steel(PM-HSS) has reportedly been a good alternative material for rolling mill because of its superior performance to conventional HSS. This paper has been aimed to investigate the possibility for application to rolling contact element for PM-HSS by X-ray diffraction technique. The X-ray elastic constant for PH-HSS has been found by X-ray diffraction during the four-point bending test. Residual stress and half-value breadth on the contact surface during rolling contact fatigue process by X-ray diffraction have also been measured. The result of this study shows that the application of X-ray diffraction technique to PM-HSS could be as possible alternative material as conventional HSS. Half-value breadth on rolling contact surface by X-ray diffraction is not changed during rolling contact fatigue process. On the other hand, the residual stress is changed. This suggests that dislocation reaction has been hardly occurred in rolling contact, depending on super-saturated carbon in PM-HSS.

X선회절에 의한 분말 고속도공구강의 구름접촉피로 해석 (Analysis of Rolling Contact fatigue for PM-High Speed Steel by X-ray Diffraction)

  • 이한영;노정균;배종수;김용진
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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    • pp.44-49
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    • 2000
  • Recently, PM-high speed steel(PM-HSS) has reportedly been a good alternative material for rolling mill because of its superior peformance to conventional HSS. This paper has been aimed to investigate the possibility for application to rolling contact element for PM-HSS by X-ray diffraction technique. The X-ray elastic constant for PM-HSS has been found by X-ray diffraction during the four-point bending test. Residual stress and half-value breadth on the contact surface during rolling contact fatigue process by X-ray diffraction have also been measured. The result of this study shows that the application of X-ray diffraction technique to PM-HSS could be as possible alternative material as conventional HSS. Half-value breadth on rolling contact surface by X-ray diffraction is not changed during rolling contact fatigue process. On the other hand, the residual stress is changed. This suggests that dislocation reaction has been hardly occurred in rolling contact, depending on supersaturated carbon in PM-HSS.

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X-선 회절을 이용한 A1 7075-T651합금의 파손해소 (Failure Analysis in Al 7075-T651 Alloy using X-ray Diffraction Technique)

  • 오세욱;박수영;부명환
    • 한국해양공학회지
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    • 제7권2호
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    • pp.103-113
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    • 1993
  • X-ray diffraction analysis technique was used for the fatigue damage analysis and fatigue life prediction in Al 7075-T651 alloy. The tensile test, fatigue strength and fatigue crack propagation test with change of stress ratio were carried out. As a result, half-value breadth was increased with the plastic deformation in the specimen increasint at all test conditions. In particular, half-value breadth at the surface of the specimens fractured by fatigue was increased as stress intensity factor range and effective stress intensity factor range were increased. In addition, the good relationship between half-value breadty and diffraction pattern was shown.

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X-ray 회절에 의한 사고파면의 정량적 해석에 관한 연구 (The Study on the Quantitative Analysis of Accident Fracture Surface by X-ray Diffraction)

  • 최성대;권현규;정선환
    • 한국정밀공학회지
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    • 제19권4호
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    • pp.117-123
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    • 2002
  • X-ray diffraction observation of fracture surfaces yields useful information to analyze the causes of failure accidents of engineering structures. This experimental technique, named X-ray fractography, has been developed especially in metal and mechanical engineering fields. The distributions of the residual stress and the half value breadth of diffraction profiles beneath the fatigue fracture surface were measured with SNCM 439, HT100 and Ti-6Al-4V alloy. The size of the maximum plastic zone was successfully determined on the basis of the measured distributions. This size was correlated to maximum stress intensity factor. The distributions of the half value breadth of diffraction profiles on the fatigue fracture surfaces were measured with SNCM 439. HT100. The equations of x-ray parameter distribution were possible to estimated fracture parameters of fatigue fracture surfaces.

X-ray PIV 기법의 개발과 혈액 유동에의 적용연구 (Development of X-ray PIV Technique and its Application to Blood Flow)

  • 김국배;이상준
    • 대한기계학회논문집B
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    • 제29권11호
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    • pp.1182-1188
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    • 2005
  • An x-ray PIV (Particle Image Velocimetry) technique was developed to measure quantitative information on flows inside opaque conduits and on opaque-fluid flows. At first, the developed x-ray PIV technique was applied to flow in an opaque Teflon tube. To acquire x-ray images suitable for PIV velocity field measurements, refraction-based edge enhancement mechanism was employed using detectable tracer particles. The optimal distance between with the sample and detector was experimentally determined. The resulting amassed velocity field data were in reasonable agreement with the theoretical prediction. The x-ray PIV technique was also applied to blood flow in a microchannel. The flow pattern of blood was visualifed by enhancing the diffraction/interference -bas ed characteristic s of blood cells on synchrotron x-rays without any contrast agent or tracer particles. That is, the flow-pattern image of blood was achieved by optimizing the sample (blood) to detector distance and the sample thickness. Quantitative velocity field information was obtained by applying PIV algorithm to the enhanced x-ray flow images. The measured velocity field data show a typical flow structure of flow in a macro-scale channel.

X-선 회절을 이용한 피로균열진전거동과 응력확대계수 예측에 관한 연구 (A Study on Prediction of Stress Intensity Factor and Fatigue Crack Growth Behavior Using the X-ray Diffraction Technique)

  • 임만배;부명환;공유식;윤한기
    • 대한기계학회논문집A
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    • 제27권5호
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    • pp.673-680
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    • 2003
  • This study verified the relationship between fracture mechanics parameters(ΔK, ΔK$\sub$eff/, K$\sub$max/) and X-ray parameters (${\alpha}$$\sub$r/, B) for SG365 steel at elevated temperature up to 300$^{\circ}C$. The fatigue crack propagation test were carried out and X-ray diffraction technique according to crack length direction was applied to fatigue fractured surface. The residual stress on the fracture surface was found to increase low ΔK region, reach to a maximum value at a certain value of K$\sub$max/ or ΔK and then decrease. Residual stress were independent on stress ratio by arrangement of ΔK and half value breadth were independent by the arrangement of K$\sub$max/. The equation of ${\alpha}$$\sub$r/ - ΔK was established by the experimental data. Therefore, tincture mechanics parameters could be estimated by the measurement of X-ray parameters.

X-선 회절을 이용한 피로균열진전거동과 응력확대계수 예측에 관한 연구 (A study on prediction of stress intensity factor and fatigue crack growth behavior using the X-ray diffraction technique)

  • 임만배;공유식;부명환;차귀준;윤한기
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.317-323
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    • 2001
  • This study verified the relationship between fracture mechanics parameters$({\Delta}K,\;{\Delta}K_{eff},\;K_{max})$ and X-ray parameters $(\sigma_r,\;B)$ for SG365 steel at elevated temperature up to $300^{\circ}C$. The fatigue crack propagation test were carried out and X-ray diffraction technique according to crack length direction was applied to fatigue fractured surface. The residual stress on the fracture surface was found to increase low ${\Delta}K$ region, reach to a maximum value at a certain value of $K_{max}\;or\;{\Delta}K$ and then decrease. Residual stress were independent on stress ratio by arrangement of ${\Delta}K$ and half value breadth were independent by the arrangement of $K_{max}$. The equation of $\sigma_r-{\Delta}K$ was established by the experimental data. Therefore, fracture mechanics parameters could be estimated by the measurement of X-ray parameters.

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X-선 회절을 이용한 피로하중을 받는 일반구조용강의 잔류응력에 관한 연구 (A Study on Residual Stress for Fatigue Fracture Surface in General Purpose Structural Steel using X-ray Diffraction)

  • 조석수;장득열;주원식
    • 한국자동차공학회논문집
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    • 제7권8호
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    • pp.248-261
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    • 1999
  • The fatigue life of mechanical components and structures has been influenced by mechanical, material and environmental conditions. It is important to search out the load type and size for accurate cause of fracture at the damaged surface of material. The fractographic method by x-ray diffraction can utilize residual stress $\sigma$_r and half-value breadth B and find out the types and the mechanical conditions of fracture. This study showed the relationship between fracture mechanical parameters $\Delta$K, $K_{max}$ and X-ray residual stress $\sigma$_r for normalized SS41 steel with homogeneous crystal structure and M.E.F. dual phase steel(martensite encapsulated islands of ferrite). The fatigue crack propagation tests were carried out under stress ratios 0.1 and 0.5. The x-ray diffraction technique according to crack propatation direction was applied to fatigue fractured surface. Residual stress $\sigma$_r was independent on stress ratios by arrangement of $\Delta$K. The equation of $\sigma$_r$\Delta$K was established by the experimental data. Therefore, fracture mechanical parameters can be estimated can be estimated by the measurement of X-ray parameters.

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X선회절에 의한 철강재료의 미Rm럼 마모형태 해석에 관한 연구(고경도강에의 적용) (Analysis of Sliding Wear Mode on Hardened Steel by X-ray Diffraction Technique)

  • 이한영
    • Tribology and Lubricants
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    • 제20권1호
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    • pp.7-13
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    • 2004
  • High strength steels are widely used as tribo-materials in the field. Previous study revealed that for mild steel, the states of strain on the worn surface measured by X-ray diffraction has a good relationship with the state of wear. The objective of this study is to identify the relationship between the state of strain on the worn surface and the state of wear in high strength steels. Sliding wear tests were carried out using several hardened steels. X-ray diffraction tests were conducted to analyze the state of strain on the worn surface during wear. The experimental results indicated that the state of strain on worn surface in the hardened steel shows the same tendency as in the mild steel. It is clear that change of half value width on the worn surface as a function of sliding speeds is broadly similar in shape to wear characteristics curve and its magnitude has a good relationship with the wear rate at two different wear modes in the hardened steel.

중성자 회절을 이용한 용접부위의 잔류응력 측정 (Residual Stress Measurement on Welded Specimen by Neutron Diffraction)

  • 박만진;장동영;최희동
    • Journal of Welding and Joining
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    • 제20권2호
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    • pp.50-58
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    • 2002
  • Residual stress is generated in the structures as a result of irregular elastic-plastic deformation during fabrication processes such as welding, heat treatment, and mechanical processing. There are several factors attributed to the origin of residual stresses, tensile or compressive. The stresses can be determined by destructive ways or nondestructive ways using X-ray or neutron diffraction. Although X-ray diffraction is a well established technique, it is practically limited to near-surface stresses. Neutrons penetrate easily into most materials and neutron diffraction permits non-destructive evaluation of lattice strain within the bulk of large specimens because the radiation is more deeply penetrating for metallic engineering components. This paper presented application of neutron diffraction technique to the residual stress measurement using 20 mm thick welded stainless steel plate($100{\times}100 \textrm{mm}^2$)