• Title/Summary/Keyword: Bending resistance

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A Study on the Chlorination and Resin Shrink Resist Finish of Wool (양모직물의 염소화/수지 방축 가공에 관한 연구)

  • Lee, Min Koo;Lee, Jae Ho;Jang, Byung Ho
    • Textile Coloration and Finishing
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    • v.3 no.2
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    • pp.1-9
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    • 1991
  • In order to improve the shrink resistance of wool, the fabric was treated with D.C.C.A.(Di-chloro Isocyanuric Acid) and Hercosett. The results obtained as follows, 1. The optimum condition for the shrink resistance of wool fabric was Hercosett concentration of about 2.0~2.5%(o.w.f), pH of 7, the curing temperature of about $140^{\circ}C$, and curing time of 3 minutes. 2. The physical properties with the experimental conditions, such as the tensile strength, bending strengh, crease recovery, tearing strengh were confirmed by measurements.

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A Study on the Formability Factors of Axisymmetric Multi-Stage Deep Drawing Processes (축대칭 다단계 딥드로잉 공정의 성형인자에 대한 연구)

  • 여은구;조선형;이용신
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.4
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    • pp.6-11
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    • 2002
  • Formability in deep drawing process depends not only on a drawability of workpiece material but also on process conditions such as die punch comer radius, lubricant conditions, punch-die clearance etc. For instance, bending resistance should be reduced by increasing die round appropriately, drawing load should be minimized by improving the lubricant condition between die and material, and blanking load should be increased by selecting a pertinent punch round and by augmenting the friction resistance in punch. In this study, a multi-stage deep drawing process is analyzed using ABAQUS. The effects of formability factors, such as die shoulder radius, punch-die clearance and friction coefficient are investigated, and the results are also discussed in detail.

Properties of AZO/Ag/AZO Multilayer Thin Film Deposited on Polyethersulfone Substrate

  • Jung, Yu Sup;Park, Yong Seo;Kim, Kyung Hwan;Lee, Won-Jae
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.1
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    • pp.9-11
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    • 2013
  • The AZO/Ag/AZO multilayer films were deposited on polyethersulfone (PES) substrate by using facing target sputtering methods at room temperature. The AZO/Ag/AZO multilayer films with polymer substrate had advantages, such as low sheet resistance, high optical transmittance in visible range and stable mechanical properties. From the results, the AZO/Ag/AZO multilayer films (50/12/50 nm) demonstrated a sheet resistance of 11 ${\Omega}/{\square}$ and average transmittance of 87% in visible range (wavelength of 380-770 nm). Moreover, the multilayer showed stable mechanical properties compared to the single-layered AZO sample during the bending test due to the existence of the ductile Ag metal layer.

A Study on the Formability Factors of Axisymmetric Multi-Stage Deep Drawing Processes (축대칭 다단계 딥드로잉 공정의 성형인자에 대한 연구)

  • 여은구;조선형;이용신
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.10a
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    • pp.280-285
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    • 2001
  • A good drawability of material itself is required. To improve the formability in deep drawing process. Besides that bending resistance should be reduced by increasing die round appropriately, drawing load should be minimized by improving the lubricant condition between die and material, and breaking load should be increased by selecting a pertinent punch round and by augmenting the friction resistance in Punch. In this study, a multi-stage deep drawing process is analyzed using ABAQUS, the effects of formability factors. Such as die shoulder radius, punch-die clearance and friction coefficient are investigated.

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Experimental study on stripping mechanism of tension controlled bolts (TC볼트의 스트리핑 메카니즘에 대한 실험적 연구)

  • 신근하
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.1
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    • pp.111-118
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    • 2000
  • Over tightening experiments of the tension-controlled bolts are carried out and the stripping mechanism is reviewed base on the observed results. There are two modes of bolt failure due to the over tightening : one the fracture of the bolt the other the thread stripping Bifurcation between these two modes is rather delicate but it seems being related with the elastic flexibility of the bolt which depends upon the unused thread length. The fracture mode occurs in the bolts with good flexibility while the latter with bad one. According to the ISO Standard some meter coarse threads like M20 and M22 have the same pitch which causes bigger fastener to less resistance in shear and bending compared with the smaller one. however since UNC thread system adapts different pitch for different nominal diameter unified coarse threads show better stripping resistance than their corresponding meter threads.

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A Study on the Properties of the Zn-Cr Alloy Films by Evaporation (진공증착법으로 제조된 Zn-Cr박막의 특성에 관한 연구)

  • Ju, Bong-Hwan;Lee, Gyu-Hwan;Gwon, Sik-Cheol;Baek, Un-Seung
    • 연구논문집
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    • s.23
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    • pp.109-120
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    • 1993
  • A study on corrosion and adhesion properties of evaporated Zn-Cr films were conducted on steel strip by two-source evaporater. Corrosion resistance of Zn-Cr coated steel was evaluated by salt spray test in 5% NaCl. Adhesion property of Zn-Cr films on steel substrate was evaluated by tape test after $180^\circC$ bending. Adhesion was improved with increasing the Cr content and reached the maximum at the Cr content of 6 to 8wt%. Corrosion resistance was enhanced with increasing the Cr content and improved by rolling Zn-Cr coated specimen, as a post-treatment.

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A Study on the Physical Properties of MgO Board for Wall System (경량 벽체용 MgO 보드의 물리적 특성에 관한 실험적 연구)

  • Kim, Soon-Ho;Kim, Hong-Yong
    • KIEAE Journal
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    • v.7 no.4
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    • pp.135-140
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    • 2007
  • In this study we settled the trouble of the MgO board of existence by this research. We changed the wooden one of the main ingredient of a board to a perlite and a mineral particle in the aluminum hydroxide group and proceeded with a study to physical character and fire resistance efficiency improvement. The result yellowing phenomenon could be improved and it was possible to reduce size decrease of pin hole and the frequency of occurrence. We found out that the in case of absorbed amount added 5~8% corresponding to the weight decreases the acrylic group emulsion suddenly. So this product is improved with the bending strength and water-resistance. After behavior stop time measurement of a mouse for experiments was measured at the time of a gas harmful effect test, an improved MgO board appeared more highly for an average of 138 seconds compared with a board of existence.

Characterization of Ionic-Polymer Metal Composite Actuators Varying Electroless Plating Method of Platinum (백금 무전해 도금 방법의 변화에 따른 이온성 고분자 및 금속 복합체 액추에이터의 특성 분석)

  • 차승은;김병목;조성환;이승기;박정호;김병규
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.12
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    • pp.601-607
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    • 2002
  • IPMC(Ionic Polymer Metal Composite)actuators were optimized for producing improved forces by changing multiple parameters including repetition of number of plating, surface electroding and additive(PVP)-treatment on reduction. The platinum electrode is deposited on the surface of the material where platinum particle stay in a dense form that appears to introduce a significant level of surface electrode resistance. Actuation tests were performed for such IPMC actuators under a low voltage. The test results show that the lower surface-electrode resistance generates higher actuation capability in the IPMC actuators. In order to investigate relaxation behavior of bending and repeatability in dry condition, the IPMC was coated by$rubber(KRATON^{TM})$to minimize the effect of water evaporation from IPMC. This actuator can be used in air with surface coating to avoid membrane drying.

Mechanical Properties & Ablation Mechanism of SiC Coated Carbon/Carbon Composite by Pack-cementation Method

  • Kim, J.I.;Oh, I.S.;Joo, H.J.
    • Carbon letters
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    • v.2 no.1
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    • pp.27-36
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    • 2001
  • The pack-cementation process is the method which is formed SiC coating layer to improve weak oxidation properties of CFRCs (carbon fiber-reinforced carbons). This method develops the anti-oxidation coating layer having no dimensional changes and good wetting properties. In this study to improve the oxidative resistance of the prepared 4D CFRCs, the surface of CFRCs is coated by SiC using pack cementation method. The mechanical properties of SiC-coated 4D CFRCs are measured by the 3-point bending test, and their ablation properties are investigated by the arc torch plasma test. From the results, it is found that both mechanical and ablation properties of SiC-coated 4D CFRCs are much better than bare CFRCs.

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Tribological Properties of Alumina/Graphite Composites (Alumina/graphite 복합체의 마찰마모 특성)

  • 백용혁;정종인;박용갑;김주영
    • Journal of the Korean Ceramic Society
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    • v.34 no.4
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    • pp.380-386
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    • 1997
  • The tribological properties of ceramics are very important in the application to engineering ceramic parts such as seal rings, pump parts, thread guides, and so on. In this study, the effects of graphite addition on the mechanical and tribological properties of alumina/graphite composites were investigated. The composites were prepared by the adding of graphite powder to the mixture of Al2O3, talc and calcium carbonate. Bending strength, water absorption, friction coefficient, the amount of worn out material at a certain time, and maximum surface roughness(Rmax) of the prepared composites were measured. Crystalline phases and microstructure were examined with XRD and SEM. The melt of Al2O3-CaO-MgO-SiO2 system was shown over 10 vol% graphite composition. As the amount of the graphite is increased, needle like crystals of mullite were formed and grown. We obtained the good properties of friction coefficients and wear resistance at the powder composition containing 15 vol% of graphite.

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