• 한국세라믹학회지
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• 제23권2호
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• pp.64-70
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• 1986

In this investigation x-ray diffraction method was mainly studied for quantitative analysis of clinker mineral composition. And also optical microscopic observation and Bogue calculation method were applied to compare with the x-ray diffraction method. In the procedure of x-ray diffraction analysis graphite monochromator automatic divergence slit and spinner for sample holder were used for minimizing the error due to the operation of the equipment. Especially the separation of overlapped peaks were proceeded by micro-processor automatically. The results of x-ray diffraction method for synthesized clinker were consistent with the Bogue value and the results of optical microscopic observation. However the results of quantitative analysis of mineral composition or commercial clinker containing solid solution of minor component were different from the Bogue value. On the other hand they agreed reasonably well with results of the optical mic-roscopic observation.

• 한국재료학회지
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• 제33권2호
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• pp.54-62
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• 2023

The most comprehensive and particularly reliable method for non-destructively measuring the residual stress of the surface layer of metals is the sin²ψ method. When X-rays were used the relationship of ε_φψ-sin²ψ measured on the surface layer of the processing metal did not show linearity when the sin²ψ method was used. In this case, since the effective penetration depth changes according to the changing direction of the incident X-ray, σ_φ becomes a sin²ψ function. Since σ_φ cannot be used as a constant, the relationship in ε_φψ-sin²ψ cannot be linear. Therefore, in this paper, the orthogonal function method according to Warren's diffraction theory and the basic profile of normal distribution were synthesized, and the X-ray diffraction profile was calculated and reviewed when there was a linear strain (stress) gradient on the surface. When there is a strain gradient, the X-ray diffraction profile becomes asymmetric, and as a result, the peak position, the position of half-maximum, and the centroid position show different values. The difference between the peak position and the centroid position appeared more clearly as the strain (stress) gradient became larger, and the basic profile width was smaller. The weighted average strain enables stress analysis when there is a strain (stress) gradient, based on the strain value corresponding to the centroid position of the diffracted X-rays. At the 1/5 I_max max height of X-ray diffraction, the position where the diffracted X-ray is divided into two by drawing a straight line parallel to the background, corresponds approximately to the centroid position.

• 암석학회지
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• 제3권1호
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• pp.34-40
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• 1994

High pressure X-ray diffraction study was carried out on a graphite to investigate its compressibility as well as any possible phase transition to the hexagonal diamond structure at room temperature. Energy dispersive X-ray diffraction method was introduced using a Mao-Bell type diamond anvil cell with Synchrotron Radiation. Polycrystalline sodium chloride was compressed together with graphite for the high pressure determinations. Because of the poor resolution of the X-ray diffraction pattern of graphite, its compressibility was estimated to be almost same as that of NaCl by graphite (002) X-ray diffraction peak only. An observation of any new peak from a possible hexagonal diamond phase seems very unplausible for its definite identification based on the present data. Alternative approaches such as an Wiggler Radiation source as well as a Large Volume high pressure apparatus will be necessary for the detailed studies on a graphite in future.

• 한국자동차공학회논문집
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• 제10권6호
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• pp.150-157
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• 2002

In textured material, diffraction angle $2{\theta}$ usually shows a nonlinear relation against $sin^2{\psi}$ due to elastic anisotropy of crystals. SPHD and SPCD steel is cold-rolled carbon steel for automobile. The characteristics X-ray for stress measurement is Cr $K_{\alpha}\;and\;Mo\;K_{\alpha}$ characteristic X-ray. The $2{\theta}-sin^2{\psi}$ diagram under elastic strain seems to have a linear behavior using regression line of data but has a nonlinear behavior in distribution of data by Cr $K_{\alpha}$ characteristic X-ray. As the plastic strain of specimen increases, the nonlinearity of $2{\theta}$ with respect to $sin^2{\psi}$ increases remarkably. On the other hand, the diffraction angle $2{\theta}$ by Mo $K_{\alpha}$ characteristic X-ray shows a good linearity on $2{\theta}-sin^2{\psi}$ diagram under plastic strain as well as elastic strain. Therefore, this paper presents the measurement of residual stress in cold-rolled carbon steel for automobile using penetration depth of Mo $K_{\alpha1}$ characteristic X-ray and multiplicity factor of crystal diffraction plane.

• 한국광물학회지
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• 제10권2호
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• pp.75-81
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• 1997

High pressure X-ray diffraction study was carried out on a natural FeO(OH)-goethite to investigate its compressibility at room temperature. Energy dispersive X-ray diffraction method was employed using Mao-Bell type diamond anvil cell with Synchrotron Radiation. MgO powder was compressed together with goethite for the high pressure determinations. Bulk modullus was determined to be 147.9 GPa by the Birch-Murnaghan equation of state under assumption of K0' of 4. This value was subjected to compare with its structural analogs and related materials.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.159-162
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• 2000

The purpose of this study is to develope an accurate procedure for measuring the glass content of fly ash produced by bituminous coal to assist in predicting their behavior in concrete. Quantitative mineralogical compositions of fly ashes were obtained by internal standard method using powder X-ray diffraction analysis. In the X-ray diffraction method, the specimen and standard fluorite were cautiously mixed and pulverized to 22$\mu$m in wet process so as to avoid the prefered orientation of the crystal and microabsorption effect of X-ray. calibration curve were fitted for several references peaks of four phases:$\alpha$-quartz. mullite, magnetite, hematite. The amount of glass was calculated by subtracting the amount of crystal phase and loss on ignition from the total amount. Glass content determined with this method ranged from 66.7 to 75.wt%.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 추계학술발표대회 개요집
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• pp.73-75
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• 2005

The objective of this study is to estimate the feasibility of X-ray diffraction method application for fatigue life assessment of the high-temperature pipeline steel such as main steam pipe, reheater pipe and header etc. in power plant. In this study, X-ray diffraction tests using various types of specimen simulated low cycle fatigue damage were performed in order to analyze fatigue properties when fatigue damage conditions become various stages such as 1/4, 1/2 and 3/4 of fatigue life, respectively. As a result of X-ray diffraction tests for specimens simulated fatigue damages, we conformed that the variation of the full width at half maximum intensity decreased in proportion to the increase of fatigue life ratio.

• 한국광물학회지
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• 제16권1호
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• pp.65-73
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• 2003

이 연구에서는 X-선 회절법으로 측정한 수소결합의 거리를 보정하는 두 가지 방법을 제시하였다 O…O 거리가 2.5 $\AA$ 이상인 수소결합의 경우는 저온에서 측정한 중성자 회절에 의한 수소결합 데이터를 이용하여 얻은 최적화 곡선 식 d(O-H)=exp((2.173-d(O…O))/0.138)+0.958을 이용하여 수소결합 거리를 보정한다. O…O 거리가 2.5 $\AA$ 이하의 짧은 수소결합의 경우는 결합원자가 최적화 방법(valence-least-squares)을 이용하는 것이 효과적이다. X-선 회절분석으로 얻은 긴 O…O 거리를 갖는 분자간 수소결합의 경우는 수소결합의 거리보정을 해주어야 한다.

• Tribology and Lubricants
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• 제18권3호
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• pp.187-193
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• 2002

The half-value breadth off-ray diffraction profile line is generally used for a factor in nondestructive hardness measuring method of steel. In this paper, the problem in using the half-value breadth for the hardness measuring method is evaluated in strain hardened steel. And new hardness measuring method using residual stress is proposed X-ray diffraction test after rolling contact fatigue test of ball bearing with inner race of various hardness are carried out to measure the distribution of residual stress and half-value breadth from surface. The result of this study shows that there is little correlation between half-value breadth and hardness in the higher strength region and in the region increasing the hardness by strain hardening. But the magnitude of residual stress on/under race after rolling contact fatigue test becomes clearly to be correlative with hardness. Thus, it is concluded that the hardness of strain hardened steel can be estimated by this relationship between residual stress and hardness.

• 광물과 암석
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• 제35권4호
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• pp.431-445
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• 2022

점토질 암석의 광물함량을 효과적이고 실용적으로 분석하는 방법을 X-선 분말회절분석 실험을 통하여 연구하였다. 점토질 암석의 X-선 분말회절 정량분석을 위해서는 측면마운팅(side mounting) 방법에 의한 무작위 배향(random orientation)의 전암(whole-rock) 분말시료의 준비가 필요하다. 또한, 암석을 구성하고 있는 점토광물의 감정을 위하여 2 ㎛ 이하 점토입도의 배향성 마운트(oriented mount)시편의 준비와 에틸렌글리콜 처리, 열처리 등의 실험과정이 요구된다. 정량분석을 위하여 RIR(reference intensity ratio)방법과 리트벨트(Rietveld) 회절도 계산 방법을 사용하였다. RIR값을 사용하여 전암 X-선 회절도로부터 총 점토 함량과 비점토광물(non-clay minerals)들의 함량을 얻을 수가 있었다. 또한, 점토입도의 배향성 X-선 회절도로부터는 각각 점토광물의 상대함량을 계산하여 이를 총 점토광물에 할당할 수가 있었다. 전암 X-선 회절의 리트벨트 방법에서는 10°(2θ) 미만의 X-선 회절 영역은 제외한 후에 리트벨트 회절도를 계산하였을 때 효과적인 정량분석 값을 얻을 수 있었다. 분석결과는 RIR방법과 리트벨트 방법이 서로 근사한 정량분석 값을 보여주었다. 따라서, 연구결과는 실험실에서의 일상적인 점토질암의 광물정량분석을 성공적으로 수행하는 것이 가능함을 지시한다. 그러나, 점토광물은 화학적 및 구조적 특정이 다른 수많은 변종이 존재하기 때문에 점토질암의 정량분석은 아직도 도전해야 하는 과제이다.