• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.102-105
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• 2008

To investigate the evolution of deformation texture during cold rolling deformation, cold rolling process on a commercial Al-5% Mg sheet was carried out at different rolling reduction ratio. The evolution of annealing texture in cold-rolled Al-5% Mg sheet was also investigated. The evolution of recrystallization texture during annealing process strongly depends on the rolling reduction ratio before heat treatment. Visco-plastic self-consistent (VPSC) polycrystal model was used to predict r-value anisotropy of the cold-rolled and annealed Al-5% Mg sheets. The change of volume fraction for the major texture components was also analyzed.

• 한국식품조리과학회지
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• 제13권1호
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• pp.7-15
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• 1997

The composition and polymeric structure of starch are the most important factors to determine the functional properties of rice. In an effort to relate the structural characteristics and its functional properties of starch in rice, molecular structural properties of starch from 6 rice cultivars were analysed. To relate the structure and function of starch the texture of Jeung-pyun made of rice were analyzed during retrogradation. The polymeric structure of rice starch was analyzed by debranching with isoamylase after gelatinization and fractionated with Sephadex G-75 gel filteration. The size fractionated debranched starch was categorized into four groups such as Fraction I, II, III and Intermediate Fraction depending in their max, The fractions with the max higher than 620 nm were designated as Fraction I, while those in the range of 600-620 nm and 540-600 nm as the Intermediate Fraction and Fraction II, respectively. The Fractions with the max lower than 540 were described as Fraction III. The average degree of polymerization (DP) of the Fraction I was estimated to be higher than 200, and those of other fractions, i.e. the Intermediate Fraction I, Fraction II and III were 150,45 and 25, respectively. The levels of Fraction I were varied from II to 35％ of total sugar. The Fraction I showed the linear relationship with the amylse contents, and the Intermediate Fraction, which might contain the mixture of short chain of amylose and debranched long chain of amylopectin, were measured to be in the range of 2.7∼8.4%. The levels of fraction II and III, both to be considered as the branches of amylopectin, were ranged 14.5∼23.6% and 39.7∼73.0%, respectively. The ratio of Fraction III to Fraction II describing the degree of branch or compactness of amylopectin was estimated to be around 4.0 for waxy varieties and around 2.0 for high amylose cultivars. With these results, it can be suggested that the degree of branch of the amylopectin may effect on amylose contents of starch or rice versa, To invertigate processing aptitude of different rice cultivars for the preparation of Jeung-pyun, its texture was analyzed by Instron, hardness, cohesiveness, elasticity, gumminess and chewiness of Jeung-pyun made of rice showed the significant relationship with the amylose content. Hardness was increased during retrogradation of product, but the relationship between hardness and amylose content due to not only difference in amylose content but also difference in structural characteristics of starch. In analysis of relationship between structure of rice starch and mechanical properties of Jeung-pyun during retrogradation elasticity did not show any relationship before retrogradation bur during retrogradation showed significant correlation. With these result, it can be suggested that the degree of branch of the amylopectin may effect on elasticity during retrogradation. However hardness, cohesiveness, gumminess and chewiness which were significant different before retrogradation, showed some correlation with structure of rice starch during retrigradation.

• 열처리공학회지
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• 제27권2호
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• pp.79-89
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• 2014

The effect of carbon on the microstructure and texture of low carbon steels was investigated in a series of 1.6 Mn-0.3Cr-0.2Mo-0.001B steels with carbon ranging from 0.021 to 0.048%. Intensity of {111} orientation increased with decreasing the carbon content, resulting in the increase in $r_m$ value. The highest $r_m$ value of 1.30 was obtained in 0.021%C steel annealed at $820{\sim}850^{\circ}C$ according to the typical galvannealing heat cycle. Martensite volume fraction was not substantially affected by the annealing temperature. It was found that the fine and uniformly distributed martensite particles which were present in amounts of about 5% volume fraction were desirable for the highest $r_m$ value. The other factor affecting the high $r_m$ value was the preferred epitaxial growth of retained ferrite with {111} orientation into austenite during cooling.

• 열처리공학회지
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• 제28권4호
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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.

• 한국전기전자재료학회논문지
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• 제16권10호
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• pp.938-945
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• 2003

We fabricated Ni-substrate for YBCO coated conductors and evaluated the effects of pressing and annealing temperature and time on texture. Ni substrate was fabricated by powder metallurgy technique and compacts were prepared by applying uniaxial or isostatic pressure. The texture of substrate made by applying cold isostatic pressure (CIP) was stronger than that by uniaxial pressure which we attribute to the fact that the CIP method provided higher density and more uniform density distribution. It was observed that the substrate annealed at 400 C showed both retained texture and recrystallized texture. On the other hand, the texture of substrate significantly improved at annealing temperature above 500 C, forming strong 4-fold symmetry, [111] II ND texture, and FWHM of 9∼10 . It is to be noted that the degree of texture was almost independent of annealing temperature (500∼1000 C) and annealing time(1∼54 min, at 1000 C). EBSD and AFM analysis indicated that 99% of grain boundaries was low angle grain boundary and RMS was approximately 3 nm, respectively. Development of strong cube texture and high fraction of low angle grain boundary of Ni-substrate made by powder metallurgy technique in our study is considered to be suitable for the application of YBCO coated conductors.

• Metals and materials international
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• 제24권6호
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• pp.1369-1375
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• 2018

In Fe-3%Si steel, the hot rolling process affects not only the hot rolling texture but also the primary recrystallization texture. Here, the effect of asymmetric hot rolling was studied by comparing the difference in the texture evolved between asymmetric and symmetric hot rolling. The effect of asymmetric hot rolling on the texture of primary recrystallized Fe-3%Si steel was also studied. The symmetric hot rolling of Fe-3%Si steel produces a rotated cube texture at the center but Goss and copper textures near the surface. Asymmetric hot rolling tends to produce Goss and copper textures even at the center like the texture near the surface. After primary recrystallization, the dominant texture at the center changes from {001} <210> to {111} <112> and the new texture has a higher fraction of the grains which make the low energy boundary with Goss grains than that of symmetric hot rolling.

• 한국재료학회지
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• 제10권9호
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• pp.629-635
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• 2000

본 논문에서는 Ti-48.5at%Al-0.96at%Mo 조성을 갖는 $\gamma$-TiAl 합금은 항온 단조 및 후속 조직제어 열처리 시 발달하는 집합조직의 변화에 관해 연구하였다. 특히, 동적 재결정 후 조직제어 열처리 온도와 시간의 증가에 따라 발생하는 lamellar volume fraction 과 집합조직 변화에 주목하여 관찰하였다. 동적 재결정 후 집합조직은 ND$\perp${302) 선분과, TD$\perp${100) 및 이에 비해 상대적으로 다소 약한{111) 성분들이 발달하였으며, 열처리 온도와 시간이 증가함에 따라 lameller volume fraction 은 증가했고 동일한 성분의 집합조직도 점차 강하게 발달함을 알 수 있었다. 하지만 상온인장시험 결과는 lameller volume fraction이 증가할수록 낮은 상온 연신을 보였는데, 이는 준 층상조직을 갖는 $\gamma$-TiAl합금의 상온인장특성이 집합조직의 영향보다는 lameller volume fractio과 같은 미세조직 특성에 더욱 강하게 영향을 받기 때문인 것으로 판단된다.

• 한국환경과학회지
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• 제11권12호
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• pp.1299-1305
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• 2002

Thirty sediment samples of the <63${\mu}{\textrm}{m}$ fraction collected from the southwestern coast of Korea were analysed for their heavy metal (Fe, Mn, Cr, Co, Cu, Ni, Zn and Pb) concentration. The results show that sediment texture plays a controlling role on the total metal concentrations and their spatial distribution. A single lM HCl extraction procedure was used in order to assess the environmental risk of heavy metals in bottom sediments. The non-residual fraction was the most abundant pool for Mn and Pb in most samples, which means that this metals are highly avaliable in these sediments. Cr, Ni, Fe, Co, Zn and Cu were mainly associated with the residual fraction, suggesting that their concentrations are controlled significantly by transport processes with the fine particles as carriers from diffuse pollution source. Concentration enrichment ratios(CER) were calculated from the non-residual contents and their values allowed us to classify the sediments according to their environmental risk.

• 한국분무공학회지
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• 제21권1호
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• pp.58-63
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• 2016

This study presents the dynamic characteristics of an impinging droplet on hydrophobic and hydrophilic surfaces with various texture area fractions. The flat surface was fabricated by using the drilling technique to make micro-meter hole-patterned surfaces, which shows hydrophobic textured surfaces. Moreover, the hydrophilic textured surfaces were manufactured by anodizing technique on the micro-meter hole-patterned surfaces to generate multi-layer surfaces. Impinging droplet experiments were conducted for various hole-patterned surfaces, with changing impact velocity and texture area fractions. It is observed that an anodizing technique increases wettability by decrease in hole diameter on the textured surfaces. However, micro-drilled surfaces decreases wettability because the hole diameter was so large that air can be trapped under the holes. In addition, the maximum spreading diameter decreases with the texture area fraction for the micro-drilled surfaces because of decrease in wettability.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.172-177
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• 2021

The microstructure and texture of three 316L foils of 25 ㎛ thickness, which were subjected to different manufacturing process, were systematically characterized using advance analytical techniques. Then, the electrochemical property of the 316L foils in simulated pressurized water reactor (PWR) solution was analyzed using potentiodynamic polarization. The results showed that final rolling strain and annealing temperature had evident effect on grain size, fraction of recrystallization, grain boundary type and texture distribution. It was suggested that large final rolling strain could transfer Brass texture to Copper texture; low annealing temperature could limit the formation of preferable orientations in the rolling process to reduce anisotropy. Potentiodynamic polarization test showed that all samples exhibited good corrosion performance in the simulated primary PWR solution.