• 제목/요약/키워드: thin-slicing

검색결과 12건 처리시간 0.029초

경취 재료의 ELID(Electrolytic In-Process Dressing) 경면 연삭 절단에 관한 연구

  • 김화영;안중환;부산대기계공학부
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.65-68
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    • 1995
  • A slicing method by thin diamond blade is widely usd slicing of hard and brittle materials such as ceramics,glass and ferrite etc.. In this study, a new slicing system which realizes highly efficient and mirror surface slicing was developed by applying ELID-grinding with metallic bond diamond blades and its performance was evaluated. Hard and brittle materials such as ceramics,glass and ferrite were used as workpiece. Metallic bond diamond blades with grit sizes #325 and #2000 were used. Experimental results show that highly efficient slicing and good mirror surface can be successfully obtained using the developed slicing system with ELID features.

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Research On Solutions To Slicing Errors In FDM 3D Printing Of Thin-walled Structures

  • QINGYUAN ZHANG;Byung-Chun Lee
    • International Journal of Internet, Broadcasting and Communication
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    • 제16권1호
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    • pp.176-181
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    • 2024
  • The desktop-level 3D printing machines makes it easier for independent designers to produce collectible models. Desktop 3D printers that use FDM (Fused Deposition Modeling) technology usually use a minimum nozzle diameter of 0.4mm. When using FDM printers to make Gunpla models, Thin slice structures are prone to slicing errors, which lead to deformation of printed objects and reduction in structural strength. This paper aims to analyze the printing model that produces errors, control a single variable among the three variables of slice layer height, slice wall thickness and filament type for comparative testing, and find a way to avoid gaps. To provide assistance for using FDM printers to build models containing thin-walled structures.

극미세 3차원 형상제작의 효율성 향상을 위한 영역분할 단면법에 관한 연구 (Sub-regional Slicing Method (SSM) to Fabricate 3D Microstructure Effectively in Nano-Stereolithography Process)

  • 박상후;임태우;양동열;이신욱;공홍진;이광섭
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.264-267
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    • 2005
  • A subregional slicing method (SSM) is proposed to increase the nanofabrication efficiency of a nano-stereolithography (NSL) process based on two-photon polymerization (TPP). The NSL process can be used to fabricate 3D microstructures via the accumulation of layers of uniform thickness; hence, the precision of the final 3D microstructure depends on the layer thickness. The use of a uniform layer thickness means that, to fabricate a precise microstructure, a large number of thin slices is inevitably required. leading to long processing times. In the SSM proposed here, however, the 3D microstructure is divided into several subregions on the basis of the geometric slope, and then each of these subregions is uniformly sliced with a layer thickness determined by the geometric slope characteristics of each subregion. Subregions with gentle slopes are sliced with thin layer thicknesses, whereas subregions with steep slopes are sliced with thick layer thicknesses. Here, we describe the procedure of the SSM based on TPP, and discuss the fabrication efficiency of the method through the fabrication of a 3D microstructure.

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폐슬러지를 이용한 SiC 합성에 관한 열역학적 고찰 (Thermodynamic Consideration for SiC synthesis by Using Sludged Silicon Powder)

  • 최미령;김영철
    • 반도체디스플레이기술학회지
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    • 제2권1호
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    • pp.21-24
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    • 2003
  • Sludged silicon powders that are generated during silicon ingot slicing process have potential usage as silicon source in fabricating silicon carbide powders by adding carbon. A thermodynamic calculation is performed to consider a plausible formation condition for the silicon carbide powders. A thin silicon oxide layer around silicon powder is sufficient to supply equilibrium oxygen partial pressure at the formation temperature($1400^{\circ}C$) of the silicon carbide in the Si-C-O ternary system. Formation of silicon carbide by using the sludged silicon powders is more efficient than by using silicon oxide powders.

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다기능 파노라마 방사선촬영장치를 이용한 하악해면골질의 평가 (Assessment of Cancellous Bone of Mandible by Multifunctional Panoramic X-Ray Machine)

  • 고재경;김재덕
    • Imaging Science in Dentistry
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    • 제30권1호
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    • pp.16-22
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    • 2000
  • Purpose : To evaluate the bone densities measured on copper-equivalent image of cross sectional view of mandibular edentulous premolar area obtained by multifuctional panoramic x-ray machine, PM 2002 CC with transversal slicing system. Materials and Methods: Panoramic cross sectional views with 8 mm focal layer of aluminum step and blocks, of hydroxyapatite (RA) step, 6 HA blocks and copper step wedge having 0.03 mm thickness of each step, and of 3 bone blocks cutted by 8 mm thickness mesiodistally and a dry mandible with copper step wedge were taken by using transversal slicing system in PM 2002 Cc. All reference-equivalent images were made and analyzed by NIH image program. Results: The average copper-equivalent value of cancellous bone of bone blocks on the panoramic cross sectional view was 0.026 ± 0.020 mm Cu. The calculated average bone density was 0.38g/cm². There was no significant difference (P>0.1) between the bone densities on intraoral digital view and on the panoramic digital cross sectional view. Conclusion: The copper-equivalent image of panoramic digital cross sectional view obtained by PM 2002 CC with very thin copper step wedge was supposed to be useful to measure the bone density of cancellous bone of mandible at the premolar edentulous area.

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Sentinel Node Biopsy Examination for Breast Cancer in a Routine Laboratory Practice: Results of a Pilot Study

  • Khoo, Joon-Joon;Ng, Chen-Siew;Sabaratnam, Subathra;Arulanantham, Sarojah
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권3호
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    • pp.1149-1155
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    • 2016
  • Background: Examination of sentinel lymph node (SLN) biopsies provides accurate nodal staging for breast cancer and plays a key role in patient management. Procurement of SLNs and the methods used to process specimens are equally important. Increasing the level of detail in histopathological examination of SLNs increases detection of metastatic tumours but will also increase the burden of busy laboratories and thus may not be carried out routinely. Recommendation of a reasonable standard in SLN examination is required to ensure high sensitivity of results while maintaining a manageable practice workload. Materials and Methods: Twenty-four patients with clinically node-negative breast cancer were recruited. Combined radiotracer and blue dye methods were used for identification of SLNs. The nodes were thinly sliced and embedded. Serial sectioning and immunohistochemical (IHC) staining against AE1/AE3 were performed if initial H&E sections of the blocks were negative. Results: SLNs were successfully identified in all patients. Ten cases had nodal metastases with 7 detected in SLNs and 3 detected only in axillary nodes (false negative rate, FNR=30%). Some 5 out of 7 metastatic lesions in the SLNs (71.4%) were detected in initial sections of the thinly sliced tissue. Serial sectioning detected the remaining two cases with either micrometastases or isolated tumour cells (ITC). Conclusions: Thin slicing of tissue to 3-5mm thickness and serial sectioning improved the detection of micro and macro-metastases but the additional burden of serial sectioning gave low yield of micrometastases or ITC and may not be cost effective. IHC validation did not further increase sensitivity of detection. Therefore its use should only be limited to confirmation of suspicious lesions. False negative cases where SLNs were not involved could be due to skipped metastases to non-sentinel nodes or poor technique during procurement, resulting in missed detection of actual SLNs.

잉곳 슬라이싱용 Saw Wire의 연삭마모에 미치는 인장특성과 미세조직의 영향 (Effects of Tensile Properties and Microstructure on Abrasive Wear for Ingot-Slicing Saw Wire)

  • 황빈;김동용;김회봉;임승호;임재덕;조영래
    • 한국재료학회지
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    • 제21권6호
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    • pp.334-340
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    • 2011
  • Saw wires have been widely used in industries to slice silicon (Si) ingots into thin wafers for semiconductor fabrication. This study investigated the microstructural and mechanical properties, such as abrasive wear and tensile properties, of a saw wire sample of 0.84 wt.% carbon steel with a 120 ${\mu}M$ diameter. The samples were subjected to heat treatment at different linear velocities of the wire during the patenting process and two different wear tests were performed, 2-body abrasive wear (grinding) and 3-body abrasive wear (rolling wear) tests. With an increasing linear velocity of the wire, the tensile strength and microhardness of the samples increased, whereas the interlamellar spacing in a pearlite structure decreased. The wear properties from the grinding and rolling wear tests exhibited an opposite tendency. The weight loss resulting from grinding was mainly affected by the tensile strength and microhardness, while the diameter loss obtained from rolling wear was affected by elongation or ductility of the samples. This result demonstrates that the wear mechanism in the 3-body wear test is much different from that for the 2-body abrasive wear test. The ultra-high tensile strength of the saw wire produced by the drawing process was attributed to the pearlite microstructure with very small interlamellar spacing as well as the high density of dislocation.

Cross-Sectional Transmission Electron Microscopy Sample Preparation of Soldering Joint Using Ultramicrotomy

  • Bae, Jee-Hwan;Kwon, Ye-Na;Yang, Cheol-Woong
    • Applied Microscopy
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    • 제46권3호
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    • pp.167-169
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    • 2016
  • Solder/electroless nickel immersion gold (ENIG) joint sample which is comprised of dissimilar materials with different mechanical properties has limited the level of success in preparing thin samples for transmission electron microscopy (TEM). This short technical note reports the operation parameters for ultramicrotomy of solder joint sample and TEM analysis results. The solder joint sample was successfully sliced to 50~70 nm thick lamellae at slicing speed of 0.8~1.2 mm/s using a boat-type $45^{\circ}$ diamond knife. Ultramicrotomy can be applied as a routine sample preparation technique for TEM analysis of solder joints.

수평 Bridgeman법으로 성장된 사파이어기판 가공 및 GaN 박막성장 (GaN epitaxial growths on chemically and mechanically polished sapphire wafers grown by Bridgeman method)

  • 김근주;고재천
    • 한국결정성장학회지
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    • 제10권5호
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    • pp.350-355
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    • 2000
  • 수평 Bridgeman방식으로 성장된 C축 방향의 사파이어 결정기판을 연마 가공하였으며, 또한 유기금속 기상화학 증착 방법으로 사파이어 기판 위에 GaN 박막을 증착하였다. 사파이어 인고트를 성장하여 2인치 사파이어 기판으로 이용하였으며 웨이퍼 절편장치 및 연마장치를 개발하였다. 이러한 다단계의 연마 가공은 기판 표면을 경면화하였다. 표면 평탄도 및 조도는 원자힘현미경으로 측정하였다. 개발된 사파이어 기판위에 성장된 GaN 박막의 특성 및 청색광소자로의 응용 가능성을 확인하였다.

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VLM-S용 선형열선절단기의 회전각 계산 (Calculation of Rotation Angle of the Linear Hotwire Cutting System for VLM-s)

  • 이상호;안동규;양동열
    • 한국정밀공학회지
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    • 제19권2호
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    • pp.87-94
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    • 2002
  • Most of Rapid Prototyping (RP) process adopt a solid Computer Aided Design (CAD) model, slicing into thin layers of uniform, but not necessarily constant, thickness in the building direction. Each cross-sectional layer is successive1y deposited and at the same time, bonded onto the previous layers; the stacked layers form a physical part of the model. The objective of this study is to develop a method for calculating the rotation angle ($$\theta$_x, $\theta$_y$) of hotwire of the cutting system in the three-dimensional space for the Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-S). In order to examine the applicability of the developed method to VLM-S, various three-dimensional shapes. such as a screw, an extruded cross, and free surface bodies such as miniatures of the monkey(a figure of Sonokong), were made using the data obtained form the method.