• Title/Summary/Keyword: Grain Texture

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Texture Evolution during Primary Recrystallization and Effect of Number of Cold Rolling Passes, Heating Rate, and Si Contents in Grain-Oriented Electrical Steel (방향성 전기강판에서 1차 재결정시 Si 함량과 냉간압연 횟수, 승온 속도에 따른 집합조직 발달)

  • Jeon, Soeng-Ho;Park, No Jin
    • Journal of the Korean Society for Heat Treatment
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    • v.31 no.6
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    • pp.269-274
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    • 2018
  • Grain-oriented electrical steel sheets are mainly used as core materials for transformers and motors. They should have excellent magnetic properties such as low core loss, high magnetic flux density and high permeability. In order to improve the magnetic properties of the electrical steel sheet, it is important to form Goss oriented grains with a very strong {110}<001> orientation. Recently, efforts have been made to develop Goss grains by controlling processes such as hot rolling, cold rolling, and primary and secondary recrystallization. In this study, the sheets containing 3.2 and 3.4wt.% Si were used, which were rolled with 1 and 10 passes with total thickness reduction of 89%. Heating was carried out for primary recrystallization with different heating rates of $25^{\circ}C/s$ and $24^{\circ}C/min$ until $720^{\circ}C$. The behavior of Goss-, {411}<148>-, and {111}<112>-oriented grains were analyzed using X-ray diffraction(XRD) and electron back-scatter diffraction(EBSD) analysis. The area fraction of Goss-oriented grains increased with the number of rolling passes during cold rolling; however, after the primary recrystallization, the area fraction of the Goss grains was higher and exact Goss grains were found in the specimens subjected to rapid heating after one rolling pass.

Measurement of Hardness and Adhesiveness of Cooked-Rice (밥블록을 이용한 찰밥의 경도 및 부착성 측정법)

  • Lee, Y.J.;Hwang, S.W.;Park, Y.S.;Yoon, W.J.;Chun, J.K
    • Applied Biological Chemistry
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    • v.38 no.5
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    • pp.398-402
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    • 1995
  • Hardness and adhessiveness of cooked rice were measured with rice grain and rice block methods by texturemeter. In grain method 3, 4 and 5 grains were arranged and subjected to the texture test with a plastic plunger at 95% strain and 0.5mm/sec speed. The hardness were 7.4kg, 7.5kg and 10.0kg respectively and the coefficient of variation ranged from 37.0% to 25.9%, which was mainly due to the irregular geometry of the grains in each specimen set Adhesiveness could not be measured with this method. A cylindrical rice block($H/D=20mm{\times}15mm$) was made for the texture analysis. The hardness was 2.1 kg with coefficient of variation ranging from 2.8 to 7.0%, and the block method was s more reproducible compared to the grain method. A grooved plastic plunger and platform were designed for the measurement of adhesiveness of cooked rice block. The adhesiveness was 0.68kg sec and the coefficient of the variation was 4.6%.

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Determining the Optimal Recipe for Long-Grain Jasmine Rice with Sea Tangle Laminaria japonica, and Its Effect on the Glycemic Index

  • Zeng, Jiting;Choi, Nam-Do;Ryu, Hong-Soo
    • Fisheries and Aquatic Sciences
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    • v.17 no.1
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    • pp.47-57
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    • 2014
  • Thai Jasmine rice (Oryza sativa, long grain Indica var.) is popular in southeastern Asia and China due to its non-glutinous, fluffy texture and fragrant smell. However it has a high starch digestibility, which leads to an increased glycemic index (GI). Therefore it may require modified cooking methods for diabetes patients. The objectives of this study were to optimize the ratio of Thai Jasmine rice, sea tangle, and olive oil (CLTR) based on consumers' acceptance. The GI of plain cooked Thai Jasmine rice (CLR) was measured as a control. Sensory evaluation and response surface methodology were used to determine the optimal ratio. Texture analysis and nutritional evaluation were also performed on the optimal recipe of cooked Jasmine rice with sea tangle. A multiple regression equation was developed in quadratic canonical polynomial models. We used 26 trained Chinese panelists in their forties to rate color, flavor, adhesiveness, and glossiness, which we determined were highly correlated with overall acceptability. The optimal CLTR formula was 34.8% rice, 2.8% sea tangle, 61.9% water, and 0.5% olive oil. Compared to CLR, CLTR had a lower hardness, but a higher springiness and cohesiveness. However, CLR and CLTR had the same adhesiveness and chewiness. The addition of sea tangle and olive oil delayed retro-gradation of starch in CLTR and increased total dietary fiber, and protein and ash contents. The degree of gelatinization, and in vitro protein and starch digestibility of CLTR were lower than those of CLR. Based on Wolver' method, the GI of CLTR (52.9, incremental area under the glycemic-response curve, ignoring the area below fasting, as used for calculating the GI [Inc]) was lower compared with that of CLR (70.94, Inc), which indicates that CLTR is effective in decreasing and stabilizing blood glucose level, owing to its lower degree of gelatinization and starch digestibility. Our results show that CLTR can contribute to the development of a healthier meal for families and the fast food industry.

Prediction of Necking in Tensile Test using Crystal Plasticity Model and Damage Model (결정소성학 모델과 손상 모델을 이용한 박판소재의 네킹 예측)

  • Kim, Jong-Bong;Hong, Seung-Hyun;Yoon, Jeong-Whan
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.8
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    • pp.818-823
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    • 2012
  • In order to predict necking behaviour of aluminium sheets, a crystal plasticity model is introduced in the finite element analysis of tensile test. Due to the computational limits of time and memory, only a small part of tensile specimen is subjected to the analysis. Grains having different orientations are subjected to numerical tensile tests and each grain is discretized by many elements. In order to predict the sudden drop of load carrying capacity after necking, a well-known Cockcroft-Latham damage model is introduced. The mismatch of grain orientation causes stress concentration at several points and damage is evolved at these points. This phenomenon is similar to void nucleation. In the same way, void growth and void coalescence behaviours are well predicted in the analysis. For the comparison of prediction capability of necking, same model is subjected to finite element analysis using uniform material properties of polycrystal with and without damage. As a result, it is shown that the crystal plasticity model can be used in prediction of necking and fracture behavior of materials accurately.

Fabrication of textured Ni substrates for coated conductor prepared by powder metallurgy and plasma arc melting method (분말법과 주조법으로 제조한 coated conductor용 Ni 기판 개발)

  • 임준형;김정호;김규태;장석헌;주진호;나완수;홍계원;지봉기;김찬중
    • Progress in Superconductivity
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    • v.5 no.1
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    • pp.70-74
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    • 2003
  • We fabricated cube textured Ni substrate for YBCO coated conductor and evaluated the effects of processing parameters on microstructural evolution and texture formation. Ni-rods as an initial specimen were prepared by two different methods, i.e., powder metallurgy(PM) and plasma arc melting(PAM). Subsequently, the rods were cold rolled to 100 $\mu\textrm{m}$ thick substrate and annealed at temperatures of $700∼1200^{\circ}C$. The texture of the substrate was characterized by pole-figure. It was observed that the texture of substrate made by P/M did not significantly varied with annealing temperature of 600∼$l100^{\circ}C$ and the full-width at half-maximums (FWHM) of both in-plane and out-of-plane were 9$^{\circ}$$10^{\circ}$. On the other hand, the texture of substrate made by PAM was more dependent on the annealing temperature and the corresponding values were $9^{\circ}$$13^{\circ}$ at the temperature range. In addition, recrystallization twin texture, (221)<221>, was formed as the temperature increased further. OM profiles showed that the grain size of substrate made by P/M was smaller than that made by PAM and this difference was correlated to the microstructure of initial specimens.

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Resistance to Airflow of Grain as Affected by Grain Moisture Content (곡물(穀物)의 함수율(含水率) 변화(變化)에 따른 송풍저항(送風抵抗)에 관(關)한 연구(硏究))

  • Kim, M.S.;Kim, S.R.
    • Journal of Biosystems Engineering
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    • v.11 no.2
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    • pp.55-65
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    • 1986
  • The resistance to the passage of airflow through various agricultural products is an important consideration in the design of an aeration or drying system. The amount of resistance to airflow varied widely from one kind of grain to another, and depended upon airflow rate, surface texture and shape of the particles, the size and configuration of voids, and foreign and fine material in the grain bed. The airflow rate was the major factor considered on this kind of study in the early stages. But these days, the studies on the resistance to airflow of grain affected by grain moisture content and foreign and fine material have been widely carried out. However the foreign an fine material in the grain bed could not be a major factor on the study in Korea because there were only a few grain process procedure after harvesting it. The objectives of this study were to investigate the effect of moisture content and airflow rate on airflow resistance to grain, and to develop a model to predict the static pressure drop across the grain bed as a function of moisture content and airflow rate. The rough rice varieties, Akibare, Milyang 15 (Japonica types), Samkwang, Backyang (Indica types)and covered barley variety, Olbori, which were harvested in 1985 were used in the experiment after cleaning them. Resistances to airflow of grain were investigated at four levels of moisture content (13-25%, wb.) for ten different airflow rates($0.01-0.15m^3/sm^2$). The results of this study are summarized as follows; 1. Theaverage bulk densities were $585.3kg/m^3$ for rough rice and $691.6kg/m^3$ for barley at the loose fill, and were $648.8kg/m^3$ for rough rice and $758.2kg/m^3$ for barley at the packed fill. The pressure drops at the packed fill beds were approximately 1.4 to 1.8 times higher than those at the loose fill beds. 2. The pressure drops across grain beds deceased with the increase of moisture content and increased with airflow rate. The decreasing rates of pressure drop across grain beds according to the moisture contents at the lower airflow rates were higher than those at the higher airflow rates, and the increasing rates of pressure drop according to the airflow rates at the lower moisture contents were higher those at higher moisture contents. 3. The pressure drop across barley bed were much higher than rough rice beds and the pressure drops across Japonica type rough rice beds were a little higher than Indica type. 4. The mathematical models to predict the pressure drop across grain beds as a function of moisture content and airflow rate were developed from these experiments.

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THE LASER-BASED AGGREGATE SCANNING SYSTEM: CURRENT CAPABILITIES AND POTENTIAL DEVELOPMENTS

  • Kim, Hyeong-Gwan;Rauch, Alanf;Haas, Carl T.
    • Construction Engineering and Management
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    • v.4 no.1 s.13
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    • pp.48-54
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    • 2003
  • An automated system for scanning and characterizing unbound aggregates, called the 'Laser-based Aggregate Scanning System'(LASS), has been developed at the University of Texas at Austin. The system uses a laser profiler to acquire and analyze true three-dimensional data on aggregate particles to measure various morphological properties. Tests have demonstrated that the system can rapidly and accurately measure grain size distribution and dimensional ratios, and can objectively quantify particle shape, angularity, and texture in a size invariant manner. In its present state of development, the LASS machine is a first-generation, laboratory testing device. With additional development, this technology is expected to provide high-quality, detailed information for laboratory and on-line quality control during aggregate production.

Effect of high Si-Fe alloy annealed in the sulfur atmosphere (고규소철 합금의 유황분위기중 열처리의 영향)

  • Koo, Jar-Myung
    • Journal of the Korean Society for Heat Treatment
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    • v.7 no.2
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    • pp.111-117
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    • 1994
  • Effect of rapidly solidfid 6.5wt%Si-Fe alloy annealed in the sulfur atmosphere were studied. The ribbons Which were showed with random structure at the received state, were developed into(110) texture in the heat treatment of the vacuum atmosphere, into (100)texture in the sulfur atmosphere. After the ribbon was continuously annealed in the vacuum atmosphere for 3 min. at $1100^{\circ}C$, and sulfur atmosphere for 1hr at $1175^{\circ}C$, grain size of (100)plane was grew to 4-8mm and the coercive force was decreased to 2-4A/m remarkably.

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Change in Microstructure and Texture during Continuous-Annealing in Dual-Phase Steels (복합조직강의 연속어닐링과정에서 미세조직과 집합조직의 변화)

  • Jeong, Woo Chang
    • Journal of the Korean Society for Heat Treatment
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    • v.28 no.4
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    • pp.171-180
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    • 2015
  • The variation in microstructure and texture during continuous annealing was examined in a series of 1.6% Mn-0.1% Cr-0.3% Mo-0.005% B steels with carbon contents in the range of 0.010 to 0.030%. It was found that microstructure of hot band consisted of ferrite and pearlite as a consequence of high coiling temperature, and eutectoid carbon content was between 0.011% and 0.016%. Martensite ranged in volume fraction from 1.5% to 4.0% when annealed at $820{\circ}C$ according to the typical continuous annealing cycle. The critical martensite content for the continuous yielding was about 4% from stress-strain curves. The continuous yielding was obtained in the 0.030% carbon steel and 0.010% to 0.020% carbon steels revealed some yield point elongation ranging from 0.8% to 2.2% in as-annealed conditions. Higher tensile strength in the higher carbon steel is due to both increase in the martensite volume fraction and ferrite grain refinement. Decreasing the carbon content to 0.01% strengthened the intensities of ${\gamma}$-fiber textures, resulting in the increase in the $r_m$ value, which was caused by the lower volume fraction of martensite. The higher carbon steels showed the lower $r_m$ value of about 1.0.

Effect of Barley Flour Addition on Quality Characteristics of Vegetable Pancake (보릿가루의 첨가가 부침개의 품질특성에 미치는 영향)

  • Lee, In-Seon
    • Korean journal of food and cookery science
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    • v.33 no.3
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    • pp.333-341
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    • 2017
  • Purpose: This study investigated the quality characteristics of vegetable pancake prepared with various levels of barley flour. Methods: The pH level and spreadability of the batters as well as the color, texture, and sensory evaluation of the vegetable pancake were analyzed. Results: The results show that spreadability of batter significantly decreased as the substitution amount of barley flour increased (p<0.001). The pH level of the batter significantly decreased as the substitution amount of barley flour increased (p<0.001). Redness and yellowness increased as the substitution amount of barley flour increased. For texture, the sample groups with substituted barley flour showed high characteristics of hardness, gumminess, and chewiness. Principal component analysis showed that the sample group with a high substitution amount of barley flour was characterized by relatively high darkness, roasted grain aroma, bitterness, astringent, and chalkiness. Acceptance test found that the sample group with 15% barley flour received higher acceptance than the sample group with 0% barley flour in terms of color, texture, and overall acceptance. Conclusion: Acceptance test found that the sample group with 15% or 30% of barley flour had significantly higher or similar acceptance attributes than the sample group without barley flour, which suggests the possibility of developing vegetable pancake with barley flour.