• Title/Summary/Keyword: B-SiC

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Elevation of quality in Zinc & Zinc-Nickel plating for Automobile Parts (자동차부품 Zn 및 Zn-Ni합금도금 품질기술향상)

  • Hwang, Hwan-Il;Kim, Yu-Sang
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2011.05a
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    • pp.204-204
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    • 2011
  • 최근 자동차수명의 연장, 고품질, 내식내마모성 향상의 요구에 따라 아연도금 및 합금도금의 친환경화, 아연합금도금특성 향상, 흑색화 실현, 아연-철, 아연-니켈 벤딩성 향상, 주석-아연 합금도금과 무전해 Ni-W-P, Ni-B-W, 전해 NiSiC-PTFE, Ni-Diamond복합도금 등의 도금현장 적용과 도금 후 3가 크로메이트 도장 밀착성에 대한 품질기술지원이 요구되고 있다.

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Magnetic Property Evolution of Co-22%Cr Alloy Thin Films with Self-Organized Nano Structure Formation (Co-22%Cr 합금박막의 자가정렬형 나노구조에 의한 자기적 물성)

  • Song, O-Seong;Lee, Yeong-Min
    • Korean Journal of Materials Research
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    • v.11 no.12
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    • pp.1042-1046
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    • 2001
  • Co-22%Cr alloy films are promising for high-density perpendicular magnetic recording media with their perpendicular anisotropy and large coercivity of 3000 Oe. We observed that a self organized nano structure(SONS) of fine ferromagnetic Co-enriched phase and paramagnetic Cr-enriched phase appears inside the grain of Co-Cr magnetic alloy thin films at the elevated substrate temperature after do-sputtering. We prepared 1000 $\AA$-thick Co-22%Cr films on 2000 $\AA$- SiO$_2$/Si(100) substrates at the deposition rate of 100 $\AA$/min with substrate temperatures of 3$0^{\circ}C$, 10$0^{\circ}C$, 15$0^{\circ}C$, 20$0^{\circ}C$, 30$0^{\circ}C$, and 40$0^{\circ}C$, respectively. We employed a vibrating sample magnetometer(VSM) to measure the B-H loops showing the saturation magnetifation, coercivity, remanence in in- plane and out- of- plane modes. In- plane coercivity, perpendicular coercivity, and perpendicular remanence increased as substrate temperature increased, how-ever they decreased after 30$0^{\circ}C$ slowly. Transmission electron microscope (TEM) characterization revealed that the self organized nano structure (SONS) appears at the elevated substrate temperature, which forms fine Co-enriched phases inside a grain, then it eventually affect the perpendicular magnetic property. Our results imply that we may tune the perpendicular magnetic properties with SONS obtained at appropriate substrate temperature.

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Effects of the Precipitation of Carbides and Nitrides on the Texture Structures in Extra Low Carbon Steel Sheets containing B, Nb and Ti(ll) (B, Nb및 Ti를 함유한 극저탄소강에서 탄화물 및 질화물의 석출이 집합조직에 미치는 영향(ll))

  • Lee, Jong-Mu;Yun, Guk-Han;Lee, Do-Hyeong
    • Korean Journal of Materials Research
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    • v.3 no.2
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    • pp.131-139
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    • 1993
  • Abstract Alloying elements such as AI, Ti, Nb and B in the extra low carbon AI-killed steel precipitate as nitrides or carbides and change the recrystallization texture structure of the steel during heattreatment with the result of strong effects on the deep drawability of the steel sheet. In this study the effects of fine precipitates such as nitrides and carbides on the texture of extra low carbon steels into which Ti, Nb, B, P, Si and Mn were added as alloying elements were investigated by means of TEM, SEM and optical microscopic analyses. Fine N$b_2$C and T$i_2$AIN precipitates are mainly observed in the steel containing both Nb and Ti, while fine AIN and coarse BN precipitates are observed in the Nb~containing steel and coarse T${i_4}{N_3}$ and ${N_10}{N_22}$/T$i_68$ precipitates are observed in the Ti-containing steel. The grain size of the Ti containing steel is larger than that of the Nb containing steel and that of the one containing both Nb and Ti.

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EFFECTS OF METHANOL-REFORMULATED FUELS ON TRANSIENT CHARACTERISTICS FOR AN SI ENGINE

  • Choi, S.H.;Kim, G.B.;Chang, Y.J.;Jeon, C.H.
    • International Journal of Automotive Technology
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    • v.5 no.4
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    • pp.311-319
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    • 2004
  • There are many methods to test engine emissions depending on the regulations used such as FTP-75(CYS-75) mode, 10-15 mode and ECE-15 mode. Most of these modes consist of transient conditions such as cranking, rapid acceleration or deceleration modes. In this experimental research, the transient characteristics including cranking and accelerating mode in SI engines were studied to compare pure gasoline with methanol-reformulated fuels for performance and exhaust emissions. The results show that methanol-reformulated fuels have a better emissions reduction rate than that of pure gasoline especially for HC, CO and NOx emissions during cranking mode. The acceleration performances conform to the results of the distillation curve and the CO concentration for RM50 varies slightly in acceleration mode.

Stability of Coated Green Phosphors for Enhancing Picture Quality of PDP

  • Han, B.Y.;Kim, J.H.;Yoo, J.S.;Kim, Y.K.;Hur, Y.K.;Choi, C.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.942-945
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    • 2006
  • The picture quality of a plasma display panel is very sensitive to the phosphor characteristics such as luminescence, decay time, surface properties, and even longevity of phosphor material in itself. In our previous work, the discharging characteristics in green cell of PDP were demonstrated to be enhanced by coating $Zn_2SiO_4:Mn^{2+}$ phosphors with positively charged metal oxide such as MgO. Here, $Zn_2SiO_4:Mn^{2+}$ phosphors were coated by various metal oxides for examining the coating effect on the picture quality. Specially, longevity while fabricating the panel was investigated for panel application in this work. Also the effects of ion and electron bombardment on the phosphor surface will be discussed in this work.

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Uniformity Optimization of TFTs Fabricated on 2-shot SLS-Processed Si Films

  • Turk, Brandon A.;Wilt, P.C. Van Der;Crowder, M.A.;Voutsas, A.T.;Limanov, A.B.;Chung, U.J.;Im, James S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1750-1755
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    • 2006
  • Nonoptimal placement of short-channel-length TFTs in large-grained polycrystalline Si films with a periodic microstructure, as for instance obtained via 2-shot SLS, can potentially lead to degradation in the overall uniformity of the resultant devices. In this paper, we explain and demonstrate that by simply introducing a well-defined misorientation between the devices and the periodic microstructure, it is possible to significantly reduce (and potentially entirely eliminate) the device nonuniformity problem that can arise from such a cause.

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Thickness Dependence of the Electrical Properties in NiCr Thin Film Resistors Annealed in a Vacuum Ambient for π - type Attenuator Applications

  • Phuong Nguyen Mai;Lee Won-Jae;Yoon Soon-Gil
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.8
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    • pp.712-716
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    • 2006
  • NiCr thin films prepared on $SiO_2/Si$ substrates at room temperature by magnetron co-sputtering technique and then annealed in a vacuum ambient $(3{\times}10^{-6}\;Torr)\;at\;400^{\circ}C$. The grain size and crystallinity of the films increased with film thickness. The resistivity of the films slightly decreases as the film thickness increases, Temperature coefficient resistance (TCR) exhibits positive values irrespective of film thickness and TCR in the range of 50 to 400 nm thickness shows suitable values for the application of 10 dB in ${\pi}-type$ attenuators.

Physical properties of ion-beam mixed Fe/Si multilayered films

  • Park, J.S.;Kim, C.O.;Lee, Y.P.;Kudryavtsev, Y.V.;Dubowik, J.;Szymanski, B.;Rhee, J.Y.
    • Journal of Korean Vacuum Science & Technology
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    • v.5 no.2
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    • pp.38-42
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    • 2001
  • We investigated physical properties of ion-beam mixed Fe/si multilayerd films(MLF) prepared by rf sputtering onto glass substrates at room temperature. Such an ion-beam treatment has led to noticeable changes in the structural and physical properties of the MLF: the formation of a new phase which is characterized by a crystalline silicide with a low coercivity and Tc = 550 K. In contrast to the as-prepared state, the ion-beam mixed MLF contains two magnetic phases. One of them is a very soft (Hc < 2 Oe), but microscopically homogeneous one with M$\sub$eff/=6.7 kG.

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