• Title/Summary/Keyword: annealing conditions

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Simulated Annealing Algorithm for Optimum Design of Space Truss Structures (입체 트러스구조물의 최적설계를 위한 SA기법)

  • 정제원;박효선
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.04a
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    • pp.102-109
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    • 1999
  • Two phase simulated annealing algorithm is presented as a structural optimization technique and applied to minimum weight design of space trusses subjected to stress and displacement constraints under multiple loading conditions. Univariate searching algorithm is adopted for automatic selection of initial values of design variables for SA algorithm. The proper values of cooling factors and reasonable stopping criteria for optimum design of space truss structures are proposed to enhance the performance of optimization process. Optimum weights and design solutions are presented for two well-blown example structures and compared with those reported in the literature.

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Excimer-Laser Annealing for Low-Temperature Poly-Si TFTs

  • Kim, Hyun-Jae
    • Journal of Information Display
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    • v.4 no.4
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    • pp.1-3
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    • 2003
  • For excimer laser annealing (ELA), energy density, number of pulses, beam uniformity, and condition of initial amorphous Si (a-Si) films are significant factors contributing to the final microstructure and the performance of low-temperature polycrystalline Si (LTPS) TFTs. Although the process and equipment have been significantly improved, the environmental factors associated with initial amorphous Si (a-Si) films and process conditions are yet to be optimized.

Influence of firing conditions after sintering treatment on superconducting characteristics of Bi(Pb)SrCaCuO system (소결 후 열처리 조건이 Bi(Pb)SrCaCuO계 초전도 특성에 미치는 영향)

  • 박용필;이성우;이준웅
    • Electrical & Electronic Materials
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    • v.4 no.4
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    • pp.293-303
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    • 1991
  • 소결 후 냉각 및 Annealing이 Bi(Pb)SrCaCuO계 초전도체의 특성에 미치는 영향에 대해 연구하였다. 소결 후 시편을 500[.deg.C]에서 5[hr] Annealing함으로써 1)미세조직이 치밀화 되었으며 고온상의 체적비가 증가하였다. 2)임계온도 및 전류밀도 특성이 향상되었다.

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Contact Resistance and Leakage Current of GaN Devices with Annealed Ti/Al/Mo/Au Ohmic Contacts

  • Ha, Min-Woo;Choi, Kangmin;Jo, Yoo Jin;Jin, Hyun Soo;Park, Tae Joo
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.2
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    • pp.179-184
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    • 2016
  • In recent years, the on-resistance, power loss and cell density of Si power devices have not exhibited significant improvements, and performance is approaching the material limits. GaN is considered an attractive material for future high-power applications because of the wide band-gap, large breakdown field, high electron mobility, high switching speed and low on-resistance. Here we report on the Ohmic contact resistance and reverse-bias characteristics of AlGaN/GaN Schottky barrier diodes with and without annealing. Annealing in oxygen at $500^{\circ}C$ resulted in an increase in the breakdown voltage from 641 to 1,172 V for devices with an anode-cathode separation of $20{\mu}m$. However, these annealing conditions also resulted in an increase in the contact resistance of $0.183{\Omega}-mm$, which is attributed to oxidation of the metal contacts. Auger electron spectroscopy revealed diffusion of oxygen and Au into the AlGaN and GaN layers following annealing. The improved reverse-bias characteristics following annealing in oxygen are attributed to passivation of dangling bonds and plasma damage due to interactions between oxygen and GaN/AlGaN. Thermal annealing is therefore useful during the fabrication of high-voltage GaN devices, but the effects on the Ohmic contact resistance should be considered.

Thermoelectric Properties of $Bi_2Te_3$, $Sb_2Te_3$ by varying annealing temperature (Thermopile, 펠티어소자에 적용할 $Bi_2Te_3$, $Sb_2Te_3$의 annealing 온도변화에 따른 박막특성 분석)

  • Kim, Hyeon-Sik;Cho, Yeon-Shik;Park, Hyo-Derk;Seo, Dae-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.212-212
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    • 2009
  • Thermoelectric devices were used to wide range of application. At present, increasing the efficiency of these devices, in particular, through the preparation of materials showing a high thermoelectric figure of merit, Z, $Bi_2Te_3$ and $Sb_2Te_3$ thin films on Si substrates are deposited by flash evaporation method for thermopile sensor applications. In order to enhance the thermoelectric properties of the thin film, annealing in high vacuum is carried out in the temperature range from 200 to $350^{\circ}C$. The microstructure of the film is investigated by XRD and SEM. The resistivity and Seebeck coefficient of the films are measured by Van der Pauw method and hot probe method respectively. At elevating annealing temperature, the crystallinity and thermoelectrical properties of films are improved by increasing the size of grains. At excessive high annealing temperatures, it is shown that Seebeck coefficient of films is decreased because of Te evaporation. By optimizing the annealing conditions, it is possible to obtain a high performance thin film with a thermoelectric properties.

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The Effect of Annealing Heat Treatment by Anodic Polarization Impedance Experiments for Cu-10%Ni Alloy

  • Lee, Sung-Yul;Moon, Kyung-Man;Jeong, Jae-Hyun;Lee, Myeong-Hoon;Baek, Tae-Sil
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.5
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    • pp.536-541
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    • 2015
  • Copper has been used extensively as an electric wire or as a base material in various types of machineries owing to its good electrical and thermal conductivity and good fabricating property, as well as its good corrosion resistance compared to iron. Furthermore, the copper-nickel alloy has significant corrosion resistance in severely corrosive environments. Although, cupro-nickel alloy shows better corrosion resistance than the brass and bronze series, this alloy also corroded in severely corrosive environments, including aggressive chloride ions, dissolved oxygen, and condition of fast flowing seawater. In this study, and annealing treatment at various annealing temperatures was carried out on the cupro-nickel (Cu-10%Ni) alloy, and the effects of annealing were investigated using electrochemical methods, such as measuring the polarization and impedance behaviors under flowing seawater conditions. The corrosion resistance increased by annealing compared to non heat treatment in the absence of flowing seawater. In particular, the sample annealed at $200^{\circ}C$ exhibited the best corrosion resistance. The impedance in the presence of flowing seawater showed higher values than in the absence of flowing seawater. Furthermore, the highest impedances was observed in the sample annealed at $800^{\circ}C$, irrespective of the present of flowing seawater. Consequently, the corrosion resistance of cupro-nickel (Cu-10%Ni) alloy in a severely corrosive environment can be improved somewhat by annealing.

Study on Electrical Characteristics of FDM Conductive 3D Printing According to Annealing Conditions (FDM 3D 전도성 프린팅 어닐링 조건 따른 전기적 특성 연구)

  • Lee, Sun Kon;Kim, Yong Rae;Yoo, Tae Jung;Park, Ji Hye;Kim, Joo Hyung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.6
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    • pp.53-60
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    • 2018
  • In this paper, the effect of different 3D printing parameters including laminated angle and annealing temperature is observed their effect on FDM conductive 3D printing. In FDM 3D printing, a conductive filament is heated quickly, extruded, and then cooled rapidly. FDM 3D Print conductive filament is a poor heat conductor, it heats and cools unevenly causing the rapid heating and cooling to create internal stress. when the printed conductive specimens this internal stress can be increase electrical resistance and decrease electrical conductivity. Therefore, This experiment would like to use annealing to remove internal stress and increase electrical conductivity. The result of experiment when 3D printing conductive specimen be oven cooling of annealing temperature $120^{\circ}C$ electrical resistance appeared decrease than before annealing. So We have found that 3D printing annealing removes internal stresses and increases the electrical conductivity of printed specimens. These results are very useful for making conductive 3D printing electronic circuit, sensor ect...with electrical conductance suitable for the application.