• 한국재료학회지
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• 제16권2호
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• pp.85-91
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• 2006

The fraction of $\varepsilon\;and\;\gamma$'-iron nitride in compound layer is predicted by x-ray diffraction using direct comparison method. The validity of formulation models was checked by comparing calculated results with metallographic analysis of iron nitride compound layer grown on steel S45C by gas nitriding. The fraction of $\varepsilon$ calculated by the three phase model, porous-$Fe_3N$/ dense-$Fe_3N$/ mixed layer with $Fe_3N\;and\;Fe_4N$, is 80 percent of that analyzed by etching technique. The $\varepsilon$ fraction predicted by mixed layer model is 122 percent of that measured by microscope.

• 한국결정학회지
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• 제13권2호
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• pp.86-90
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• 2002

X-선 회절법을 이용하여 N-(Diphenylmethylene)aminomethylphosphonate의 결정 구조를 규명하였다. 이 결정의 결정계는 삼사정계이며 공간군은 P(equation omitted)이다. 단위포 상수는 a＝8.967(2) (equation omitted), b＝9.309(2) (equation omitted), c＝ 10.981(2) (equation omitted), α＝101.42(2)°, β＝92.22(2)°, γ＝92.23(2)°, V=896.8(3) (equation omitted), T＝296 K, Z＝2, D/sub c/＝1.227 Mgm/sup -3/이다. 회절반점들의 세기는 Enraf-Nonius CAD-4 Diffracto-meter로 얻었으며 MoKα선(λ＝0.7107(equation omitted))을 사용하였다. 분자 구조는 직접법으로 풀었으며, F/sub o/>4σ(F/sub o/)인 979개의 독립 회절 데이터에 대하여 최소자승법으로 209개의 변수를 정밀화하여 최종 신뢰도 값 R＝7.3%을 얻었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2000년도 추계학술발표강연 및 논문개요집
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• pp.155-155
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• 2000

• 한국정밀공학회지
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• 제21권5호
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• pp.158-165
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• 2004

Up to now, many crack repair techniques have been developed for inhibiting crack growth in structural components. However, the simplest way for inhibiting crack growth is to apply a indentation at the crack tip or at some distance ahead of the expected crack growth path so as to produce residual compressive stresses that can reduce the effective stresses around the crack tip. In spite of its importance to the aerospace industry, little attention has been devoted to evaluation of the indentation residual stress effect on the fatigue crack initiation life quantitatively. Therefore, in the present work, the magnitude and distribution of the indentation residual stresses were investigated in order to estimate the beneficial effect on fatigue crack initiation by using finite element method. Furthermore, to examine the validity of finite element analysis results, residual stress distribution in the indented specimen was measured by using X-ray diffraction technique, and fatigue crack behavior at fastener hole in aluminum alloy 7075-T6 before and after indentation processes was investigated.

• 한국자기학회지
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• 제8권4호
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• pp.198-202
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• 1998

AlxFe3-xO4를 직접합성법으로 제조하여 x-선 회절법과 Mossbauerqnsrhkd법으로 연구하였다. Mossbauer spectrum에서 subspectrum 흡수면적비에 의하여 이온분포를 졀정하였다. 팔면체자리(B-site)에 들어 있는 Fednjs자는 Aldnjs자의 첨가량과 관계없이 hopping Fe2+ (Fe3+,Al3+)에 의한 Fe2.5+의 전하상태에 있다.

• 한국안전학회지
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• 제17권4호
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• pp.71-79
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• 2002

It was attempted to evaluate the degree of degradation of thermally aged 2.25-1Mo steek by ultrasonic monlinear parameter(UNP) measurement and X-ray diffraction analysis of extracted carbide. Artificial aging was performed to simulate the microstructural degradation in 2.25Cr-1Mo steel arising from long time exposure at $540{\circ}C$. Microstructural analysis (number of carbides per unit area) and measurements of mechanical properties(Vickers hardness, DBTT) and degradation evaluation parameters(UNP and intensity ration of X-ray diffraction peak of electrolytically extracted carbide) were performed. Both of UNP and intensity ratio of X-ray diffraction peak for M6C carbide to that of M23C6 carbide(IR) increased abruptly in the initial 1000 hour of aging and then changed little. UNP and IR were proposed as potential parameters to evaluate the degree of aging degradation of 2.25Cr-1Mo steel.

• 한국재료학회지
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• 제10권9호
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• pp.642-647
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• 2000

Ni-36at.%Al을 함유하는 나도 결정립의 NiAl 합금이 기계적 합금화법에 의해 제조되었다. 제조된 분말은 방전 플라즈마 소결법에 의해 만들어졌다. 상변테에 영향을 주는 인자는 냉각속도와 열처리 시간의 조건으로 논의되었다. 소결체의 상변태 거동은 시차 열분석(DSC)과 X-선 회절(XRD) 분석법에 의해 조사되었다. 미세구조는 주사전자현미경(SEM)으로 관찰되었다. 마르텐사이트 격사상수와 체적 분율은 X-선 회절분석법 중 직접비교법에 의해 계산되었다.

• Applied Biological Chemistry
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• 제26권4호
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• pp.266-268
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• 1983

Dergree of gelatinization during cooking of Akibare(Janponica) and Milyang 23(Indica) rice was determined by X-ray diffractometry using a buit-in internal standard approach. The metod had a total coefficient of Variation of 99.9%. Milyang 23 showed slightly higher degree of gelatinization than Akibare during cooking at $100^{\circ}C$. Both rice was completely gelatinized after 20 minute cooking.

• Journal of the Korean Wood Science and Technology
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• 제20권1호
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• pp.38-45
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• 1992

Fine and alkali-swollen structures of native cellulose fibers were investigated by x-ray diffraction methods. The results of fine structures are shown in Table 1. In meridional x-ray diffractograms, the relative intensity ratio R of (002) to (004) for cellulose I was ca. 0.05 and for regenerated cellulose it was ca. 0.45. It was considered that the transformation from cellulose I to cellulose II resulted from the packing or conformational change of cellulose chain. Finally. although cellulose I was not detected in the alkali-swollen celluloses treated for 1 hr to 24 hrs, washing and drying them resulted in the generation of considerable amounts of cellulose I and the amount decreased with increasing alkali duration.

• 대한기계학회논문집A
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• 제35권10호
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• pp.1179-1185
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• 2011

용접이음부의 신뢰성 확보는 구조물의 건전성과 내구성에 직접적인 영향을 미치기 때문에 점용접 이음재의 피로설계기준(fatigue design criterion)을 정하기 위해서는 정확한 응력해석과 체계적인 피로강도평가가 필요하다. 따라서 본 연구에서는 실제 전동차량 차체에 많이 적용되는 냉간 및 열간압연강판인 SPCC, SPCE, SPHE을 대상으로 기하학적 인자(geometrical factors)들을 선별해서 TS형과 CT형의 대표적인 점용접 이음재 시험편을 기본모델로 하여 인장전단하중을 가하여 피로강도 및 피로특성을 평가하고자 하였다. 그리고 피로균열의 발생과 성장 기구에 대한 영향을 분석하기위해 용접 시 발생되는 여러 가지 주요인자들 중 입열량에 의해 발생할 수 있는 용접잔류응력을 X-ray 회절법에 의해 실험적으로 해석하였다. 그리고 이러한 해석을 통하여 얻어진 결과를 중첩(superposition)함으로 해서 잔류응력을 고려했을 경우 너깃 단 최대주응력으로 피로강도를 재평가하여 합리적인 피로설계기준(fatigue design criterion)을 재정립하고자 하였다.