• 제목/요약/키워드: consolidation process

검색결과 333건 처리시간 0.021초

자기펄스 압축성형법에 의한 다이아몬드 공구용 세그먼트 분말 성형 (Consolidation of Segment Powder for Diamond Tool by Magnetic Pulsed Compaction)

  • 윤종수;이정구;이민구;이창규;박문석;홍순직
    • 한국분말재료학회지
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    • 제15권5호
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    • pp.378-385
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    • 2008
  • This article presents the successful consolidation of the mixed Co and Diamond powders for a drilling segment by the combined application of magnetic pulsed compaction (MPC) and subsequent sintering, and their properties were analyzed. Homogeneous hardness (Hv 220) and density (97%) of sintered bulks fabricated by MPC were obtained by the new technique, where higher pressure has been employed for short period of time than that of general process. A fine microstructure and homogeneous hardness in the consolidated bulk were observed without cracks. Relatively higher drilling speed of 9.61 cm/min and life time of 6.55 m were found to the MPCed specimens, whereas the value of the specimens fabricated by general process was 11.71 cm/min and 7.96 m, respectively. A substantial improvement of mechanical properties of segment was achieved through this study.

자기펄스 압축성형법으로 성형된 Ag-SnO2 접점소재의 미세조직 및 특성 (Microstructure and Characteristics of Ag-SnO2 Contact Materials Prepared by Magnetic Pulsed Compaction)

  • 박종석;김영재;이민하;이효수;홍순직;이진규
    • 한국분말재료학회지
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    • 제18권4호
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    • pp.372-377
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    • 2011
  • In this study, we reported the microstructure and properties of Ag-$SnO_2$ contact materials fabricated by a controlled milling process with subsequent consolidation. The milled powders were consolidated to bulk samples using a magnetic pulsed compaction process. The nano-scale $SnO_2$ phases were distributed homogeneously in the Ag matrix after the consolidation. The relative density and hardness of the Ag-$SnO_2$ contact materials were 95~96% and 89~131 Hv, respectively.

점성토의 변형특성 평가를 위한 새로운 응력경로시험기법 (A New Stress Path Testing Scheme To Estimate Clay Deformation Characteristics)

  • 최영태;김창엽;정충기
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 가을 학술발표회 논문집
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    • pp.303-310
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    • 2000
  • A new stress path testing scheme with back pressure equalization process is proposed, to compute the settlement of clay soils based on their probable deformation mode. The proposed testing scheme minimizes the efforts for testing, otherwise numerous testing works are required to simulate the probable stress paths in the field. Furthermore, the proposed testing scheme can supply anisotropic stress paths for consolidation which cannot be possible in a conventional way. The validity and effectiveness of the proposed testing scheme was investigated and confirmed with test results on remolded kaolinite clay soils. Conclusively, it is suggested that the proposed testing scheme is a very effective tool to compute settlement of clay soils and it is also very useful to investigate the anisotropic characteristics of deformation of clay soils.

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Sri-Lanka내 Peat Soil의 일차압밀 및 이차압축 침하특성에 관한 연구 (A study on the characteristics of primary and secondary settlement for a peat soil in Sri-Lanka)

  • 진성기;이재원
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2004년도 춘계학술발표회
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    • pp.235-242
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    • 2004
  • For this study, a Peliyagoda area located on a route was selected among many sections of a CKE(Colombo to Katunayake Expressway) route in Sri-Lanka. Its subground consists of a very weak and thick peat soil named amorphous or fibrous peat. All of data, obtained in the design process of soft ground treatment were analyzed to evaluate the settlement characteristics resulted from an embankment load and to present reasonable methods for estimation of secondary compression settlement. For these purposes, soil parameters were used obtainedby field and laboratory tests the settlement analyses were conducted base on the field monitoring results within 20 months. In addition, Reasonable methods were studied to estimate primary consolidation and secondary compression settlement.

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FHD 공정에 의한 저손실 실리카 슬랩 도파로 형성 (Fabrication of Low Loss Silica Slab Waveguide by Flame Hydrolysis Deposition)

  • 심재기;김태홍;신장욱;박상호;김덕준;성희경
    • 한국세라믹학회지
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    • 제37권6호
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    • pp.524-529
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    • 2000
  • Silica slab wavegudie was fabricated on Si substrates by FHD for planar optical passive devices. The slab waveguide consists of lower clad and core layers, where core layer index is controlled by GeO2 addition. Doping of GeO2 in silica is difficult because of the low deposition density due to nonspherical particle generation in FHD process. Silica core particles deposited at various conditions such as flame temperature and substrate scanning were analyzed by SEM and TEM. As the flame temperature increased, the surface roughness of the core layer was decreased up to 3.6 nm after consolidation. Index difference and thickness of core of slab waveguide were 0.3%, 8$\mu\textrm{m}$ respectively. Measured optical loss at TE mode was <0.04 dB/cm at 1.3$\mu\textrm{m}$ and <0.06 dB/cm at 1.55$\mu\textrm{m}$.

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고온진공가압 티타늄 금속기 복합재료의 미시-기계적 특성에 관한 연구 (A Study on the Micro-mechanical Characteristics of Vacuum Hot Pressed Titanium Metal Matrix Composites)

  • 하태준;김태원
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2003년도 추계학술발표대회 논문집
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    • pp.207-210
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    • 2003
  • Vacuum hot pressing has been used for the development of Ti-MMCs using foil-fiber-foil method, and subsequent micro-mechanical characteristics of the composites are evaluated by means of several experimental processes. As shown by the results, fiber strength degradation occurs during the consolidation, and particularly residual stresses results from the thermal expansion mismatch between fiber and matrix materials during cooling process are incorporated in the changes of mechanical properties of the composites. In industrial applications, the processing conditions avoiding micro-material failures are important together with the properties of finished products, and therefore should be included in the assesment of the material characterization.

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수명배수공법에 있어서 부압의 영향에 관한 실험적 연구 (The Effects of Negative Pressure on Horizontal Drain Method)

  • 김정기;김지용;정승용;김수삼
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 봄 학술발표회 논문집
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    • pp.551-558
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    • 2001
  • The horizontal drain method is one of methods improving reclamation ground. This method reduces consolidation time by using drained installed horizontally, and negative pressure is applied on end of these drains by vacuum pump. But, effective negative pressure still wasn't evaluated in applying this method to reclamation ground. To estimate optimum negative pressure, soil box test that make a model the in-situ by installing horizontal drains in the center is performed pressing different vacuum pressure In the laboratory, and the variations in settlement and volume of drained water through the drains during consolidation process were measured. Also, water content with distance from drain and with depth is measured after the test.

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