• 제목/요약/키워드: Roll Bonding

검색결과 81건 처리시간 0.034초

Ni계 합금분말 용사 코팅기술을 적용한 롤 제조기술 연구 (A Study on the Roll Manufacturing Technology Applying Powder Flame Spray Coating Technology of Ni-Based Alloy Powder)

  • 박지웅;김순국;반계범
    • 한국분말재료학회지
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    • 제29권2호
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    • pp.123-131
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    • 2022

  • The purpose of this study is to improve the mechanical properties and develop manufacturing technology through self-soluble alloy powder flame spray coating on the surface of a run-out table roller for hot rolling. The roller surface of the run-out table should maintain high hardness at high temperatures and possess high wear, corrosion, and heat resistances. In addition, sufficient bonding strength between the thermal spray coating layer and base material, which would prevent the peel-off of the coating layer, is also an important factor. In this study, the most suitable powder and process for roll manufacturing technology are determined through the initial selection of commercial alloy powder for roll manufacturing, hardness, component analysis, and bond strength analysis of the powder and thermal spray coating layer according to the powder.

  • https://doi.org/10.4150/KPMI.2022.29.2.123 인용 PDF KSCI

EBSD측정에 의한 반복겹침접합압연된 무산소동의 두께방향으로의 미세조직 변화 분석 (Microstructural Evolution Analysis in Thickness Direction of An Oxygen Free Copper Processed by Accumulative Roll-Bonding Using EBSD Measurement)

  • 이성희;임차용
    • 한국재료학회지
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    • 제24권11호
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    • pp.585-590
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    • 2014

  • Microstructural evolution in the thickness direction of an oxygen free copper processed by accumulative rollbonding (ARB) is investigated by electron back scatter diffraction (EBSD) measurement. For the ARB, two copper alloy sheets 1 mm thick, 30 mm wide and 300 mm long are first degreased and wire-brushed for sound bonding. The sheets are then stacked and roll-bonded by about 50% reduction rolling without lubrication at an ambient temperature. The bonded sheet is then cut to the two pieces of the same dimensions and the same procedure was repeated on the sheets up to eight cycles. The specimen after 1 cycle showed inhomogeneous microstructure in the thickness direction so that the grains near the surface were finer than those near the center. This inhomogeneity decreased with an increasing number of ARB cycles, and the grain sizes of the specimens after 3 cycles were almost identical. In addition, the aspect ratio of the grains decreased with an increasing number of ARB cycles due to the subdivision of the grains by shear deformation. The fraction of grains with high angle grain boundaries also increased with continuing process of the ARB so that it was higher than that of the low angle grain boundaries in specimens after 3 cycles. A discontinuous dynamic recrystallization occurred partially in specimens after 5 cycles.

  • https://doi.org/10.3740/MRSK.2014.24.11.585 인용 PDF KSCI

반복겹침접합 압연공정에 의해 제조한 초미세립 AA1050/AA5052 복합알루미늄합금판재의 어닐링 특성 (Annealing Characteristics of Ultrafine Grained AA1050/AA5052 Complex Aluminum Alloy Sheet Fabricated by Accumulative Roll-Bonding)

  • 이성희;이광진
    • 한국재료학회지
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    • 제21권12호
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    • pp.655-659
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    • 2011

  • An ultrafine grained complex aluminum alloy was fabricated by an accumulative roll-bonding (ARB) process using dissimilar aluminum alloys of AA1050 and AA5052 and subsequently annealed. A two-layer stack ARB process was performed up to six cycles without lubricant at an ambient temperature. In the ARB process, the dissimilar aluminum alloys, AA1050 and AA5052, with the same dimensions were stacked on each other after surface treatment, rolled to the thickness reduction of 50%, and then cut in half length by a shearing machine. The same procedure was repeated up to six cycles. A sound complex aluminum alloy sheet was fabricated by the ARB process, and then subsequently annealed for 0.5h at various temperatures ranging from 100 to $350^{\circ}C$. The tensile strength decreased largely with an increasing annealing temperature, especially at temperatures of 150 to $250^{\circ}C$. However, above $250^{\circ}C$ it hardly decreased even when the annealing temperature was increased. On the other hand, the total elongation increased greatly above $250^{\circ}C$. The hardness exhibited inhomogeneous distribution in the thickness direction of the specimens annealed at relatively low temperatures, however it had a homogeneous distribution in specimens annealed at high temperatures.

  • https://doi.org/10.3740/MRSK.2011.21.12.655 인용 PDF KSCI

Effects of Stock Characteristics on Paper Bulk

  • Lee, Jin-Ho;Park, Jong-Moon
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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    • pp.423-426
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    • 2006

  • Paper has fibers and fines network structure and it is strongly affected by interface bonding between fibers. Depending on the inter-fiber bonding, paper bulk is determined. Fines play an important roll in Campbell and consolidation effect through wet pressing and drying operations. Refined Sw-BKP, Hw-BKP and BCTMP fines were used to investigate the fines effect. Wet-web strength, breaking length, scattering coefficient, and hydrodynamic specific volume were measured. According to the result of experiments, chemical and morphological compositions of fines do not strongly affect to wet-web forming, but strongly affect to drying operations which form hydrogen bonding among fiber-fines-fiber matrixes. Paper bulk should be controlled by the extent of hydrogen bonding between fibers during drying operations.

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