• 제목/요약/키워드: microstructure

검색결과 8,050건 처리시간 0.031초

대두(조사)의 발효에 의한 미세구조 변화에 관한 연구 (Studies on the Microstructure of Soybean (Irradiated) During Fermentation)

  • 허윤행
    • 환경위생공학
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    • 제1권1호
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    • pp.31-40
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    • 1986
  • It was observed by electron microscope (transmission electron microscope, Scanning electron microscope) as a study on microstructure of soybean after r-ray irradiation with the intensity of 5KGY, 7KGY, 10KGY and 15KGY, fermented with the named Bacillus subtilis SCF, which newly separated and identified. According to the progress fermentation, changes of soybean microstructure have been increased, especially irradiated soybeans more increased than non-irradiated them. Observation of microstructure by electron microscope showed that each protein body became more. expanded in the dimension and decomposed, spherosome around the protein body in unit area dispersed and dwindled in the numbers of it. As the fermentation on progress, changes of soybean microstructure were suitable on fermentation period of 7KGY soybean, 48-72hrs fermentation.

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Analytical Quantification and Effect of Microstructure Development in Thick Film Resistor Processing

  • Lee, Byung Soo
    • 마이크로전자및패키징학회지
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    • 제19권4호
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    • pp.33-37
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    • 2012
  • Microstructure developments of $RuO_2$ based thick film resistors during firing as a function of glass viscosity were analytically quantified and its effect on the electrical property was investigated. The microstructure development was retarded as the viscosity of glass was increased. It was found that the viscosity range for each stage of microstructure development are as follows ; $7500-10^5Pa{\cdot}s$ for the glass sintering, $2000-7500Pa{\cdot}s$ for the glass island formation, $700-2000Pa{\cdot}s$ for the glass spreading, and $50-700Pa{\cdot}s$ for the infiltration. The sheet resistivity decreased as the viscosity of glass in the resistor film increased due to the higher chance of sintering for the conductive particles with the higher viscosity of the glass.

다중압출공정을 이용한 Cu-Ni-Zr-Ti 비정질 복합재의 미세조직제어 (Microstructure Control of Cu-Ni-Zr-Ti Metallic Glass Composites by Multi-Pass Extrusion Process)

  • 김택수;이진규
    • 소성∙가공
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    • 제16권5호통권95호
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    • pp.386-390
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    • 2007
  • In order to, simultaneously, synthesize and control the size of microstructure of amorphous/crystalline composites, a repeated extrusion process was performed using the gas atomized $Cu_{54}Ni_6Zr_{22}Ti_{18}$ metallic glass powders and the crystalline brasses. The size of microstructure in the resultant composites was varied depending on the pass of extrusion as well as on the area reduction ratio. The microstructure could be estimated using an equation of $r_n=r_{n-1}/R^{1/2}$, where R is reduction ratio and $r_n$ is the resultant radius of the extruded bar after n pass. Theory of microstructural refinement as well as the relationship between the resultant microstructures and mechanical properties was discussed.

결정 소성 시뮬레이션을 이용한 프레팅 접촉에서의 마이크로 구조 영향에 관한 연구 (The Study of Microstructure Influence at Fretting Contacts using Crystal Plasticity Simulation)

  • 고준빈;고충현;이기석
    • 한국정밀공학회지
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    • 제22권8호
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    • pp.84-91
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    • 2005
  • The role of microstructure is quite significant in fretting of Ti-6Al-4V since its material properties depend strongly on crystallographic texture. In this study, we adopt crystal plasticity theory with a 2-D planar triple slip idealization to account fur microstructure effects such as grain orientation distribution, grain geometry, as well as $\alpha$ colony size. Crystal plasticity simulations suggest strong implications of microstructure effects at fretting contacts.

재가열 공정과 유도 가열의 FEM 해석 (Reheating Process and FEM Analysis of Inductive Heating)

  • 손영익
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 춘계학술대회논문집
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    • pp.195-198
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    • 1999
  • For the thixoforming process beside an existing solidus-liquidus interval, the reheating conditions to obtain the globular microstructure are very important. It relies on the control of globular microstructure of semi-solid alloys that contain non-dendritic particles. To obtain the globular microstructure in cross section of billet, the optimal design of the induction coil is necessary. Therefore, in this paper the optimal coil design to minimize electromagnetic end effect will be proposed. The results of coil design were also applied to the reheating process to obtain a fine globular microstructure. Finally, reheating data base of aluminum alloys for thixoforming and FEM model for induction heating based on the optimal coil design have been proposed.

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알루미늄소재의 만용융성형 공정에서 구상화의 크기가 기계적 성질에 미치는 영향 (The Effect of Globule size on the Mechanical Properties in Semi-Solid Forming of Aluminium Alloys)

  • 박상문;강충길
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2002년도 춘계학술대회 논문집
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    • pp.21-24
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    • 2002
  • One of the factors influences on microstructure of semi-solid product is forging pressure. Generally, the more forging pressure makes the more fine microstructure in semi-solid compression test. The microstructure and mechanical properties were investigated according to the forging pressure. The applied pressure is 110MPa, 140MPa and 170MPa, respectively. Heat treatment conditions also influence to the microstructure and mechanical properties of semi-solid product. T6 heat treatment was performed and the evaluation of microstructure and mechanical properties was investigated according to the aging time in T6 heat treatment.

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탄화물의 첨가가 고속도강의 HIP과 마모에 미치는 영향 (EHect of Carbide Addition on Riping and Wear Properties of HSS)

  • 김득중
    • 한국분말재료학회지
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    • 제3권3호
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    • pp.188-195
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    • 1996
  • In recent times the potential application of the high speed steel produced by HIP process for wear resistant and cutting materials are increasing. In this work the microstructure of Anval 30 produced by HIP process was investigated and the effect of WC, TiC addition on microstructure formation and wear properties were studied. After HIP process at 1150 $^{\circ}C$, the original feature of spherical raw powders was not removed and consequently, nonuniform microstructure was formed. However the WC added by simple powder mixture incereased the sinterbility of high speed steel and uniform microstructure formed. The wear characteristics of Anval 30 with carbide addition were tested at RT and $600^{\circ}C$. The uniform microstructure played an more important role in wear resistance as compared with the hardness.

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저변형률속도에서 ARB가공된 무산소동의 미세조직 및 기계적 성질 (Microstructure and Mechanical Properties of Oxygen Free Copper Processed by ARB at Low Strain Rate)

  • 이성희;한승전;임차용
    • 한국재료학회지
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    • 제17권10호
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    • pp.521-525
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    • 2007
  • The microstructure and mechanical properties of an oxygen free copper processed by accumulative roll bonding(ARB) at low strain rate were studied. The copper sheets were highly strained up to an equivalent strain of ${\sim}6.4$ by ARB process at ambient temperature. The strain rate of the copper during the ARB was $2.6sec^{-1}$. The microstructure and mechanical properties of the ARB-processed copper were compared to those of the specimens processed by ARB at relatively high strain rate ($37sec^{-1}$). The microstructure and mechanical properties of the copper with ARB process was very similar to each other despite of some differences in recovery.

The microstructure and mechanical performance of high strength alloy steel X2M

  • Manigandan, K.;Srivatsan, T.S.;Freborg, A.M.;Quick, T.;Sastry, S.
    • Advances in materials Research
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    • 제3권1호
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    • pp.283-295
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    • 2014
  • In this paper, the microstructure, hardness, tensile deformation and fracture behavior of high strength alloy steel X2M is presented anddiscussed. The influence of both composition and processing on microstructure of the as-provided material and resultant influence of microstructure, as a function of orientation, on hardness, tensile properties and final fracture behavior is highlighted. The macroscopic mode and intrinsic microscopic features that result from fracture of the steel specimens machined from the two orientations, longitudinal and transverse is discussed. The intrinsic microscopic mechanisms governing quasi-static deformation and final fracture behavior of this high strength steel are outlined in light of the effects oftest specimen orientation, intrinsic microstructural effects and nature of loading.

Analytical Method for Determination of Microstructure of SBR and SBR Content in Blended Rubber Composites Using Pyrolytic Technique

  • Eunji Chae;Sung-Seen Choi
    • Elastomers and Composites
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    • 제57권4호
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    • pp.188-196
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    • 2022
  • Styrene-butadiene rubber(SBR) is a copolymer of styrene and butadiene. It is composed of 1,2-unit, 1,4-unit, and styrene, and its properties are dependent on its microstructure. In general, rubber composites contain a single rubber or a blended rubber. Similarly, SBR is used by mixing with natural rubber(NR) and butadiene rubber(BR). The composition of a rubber article affects its physical and chemical properties. Herein, an analytical method for determining the microstructure of SBR using via pyrolysis is introduced. Pyrolysis-gas chromatography/mass spectrometry is widely used to analyze the microstructure of polymeric materials. The microstructure of SBR can be determined by analyzing the principal pyrolysis products formed from SBR, such as 4-vinylcyclohexene, styrene, 2-phenylpropene, 3-phenylcyclopentene, and 4-phenylcyclohexene. An analytical method for determining the composition of SBR/NR, SBR/BR, and SBR/NR/BR blends via pyrolysis is introduced. The composition of blended rubber can be determined by analyzing the principal pyrolysis products formed from each rubber component.