• 제목/요약/키워드: Surface Heat Treatment

검색결과 1,651건 처리시간 0.03초

질화포텐셜 제어 가스질화로 개발(I) : 제어질화 및 국내 기술 현황 (Development of Controlled Gas Nitriding Furnace : Controlled Gas Nitriding Technology and Present Situation in Korea)

  • 이원범;손석원
    • 열처리공학회지
    • /
    • 제36권1호
    • /
    • pp.40-46
    • /
    • 2023
  • Controlled nitriding is a technology that controls the nitriding potential based on the gas partial pressure received through an IOT-based sensor. Controlled nitriding is characterized by easy control of the phase of the nitride compound and excellent reproducibility of quality. In particular, it is possible to form a compound layer of excellent quality with fewer pores on the surface. However, despite these advantages, the application of controlled nitriding still needs to be improved in Korea. This paper explains the characteristics of controlled nitriding and describes the future direction and the problems of controlled nitriding in Korea.

산질화 표면에서 액적의 증발열전달 특성 (Evaporative Heat Transfer Characteristics of Droplet on Oxi-nitriding Surface)

  • 김대윤;이성혁
    • 한국분무공학회지
    • /
    • 제21권1호
    • /
    • pp.53-57
    • /
    • 2016
  • The present study aims to experimentally investigate the evaporative heat transfer characteristics of Oxi-nitriding SPCC surface. Moreover, the heat transfer coefficient was examined with respect to surface temperature during droplet evaporation. In fact, the nitriding surface showed significant enhancement for anticorrosion performance compared to bare SPCC surface but the thermal resistance also increased due to the formation of compound layer. From the experimental results, the evaporative behavior of sessile droplet on nitriding surface showed similar tendency with the bare surface. Total evaporation time of sessile droplet on the nitriding surface was delayed less than 5%. The difference in heat transfer coefficient increased with the surface temperature, and the maximum difference was estimated to be around 11% at $80^{\circ}C$ surface. Thus, this nitriding surface treatment method could be useful for seawater heat exchanger industries.

전해도금법을 이용한 SnO2 제조 및 후 열처리가 전지 특성에 미치는 영향 (Preparation of SnO2 Film via Electrodeposition and Influence of Post Heat Treatment on the Battery Performances)

  • 김령희;권혁상
    • 열처리공학회지
    • /
    • 제30권2호
    • /
    • pp.61-66
    • /
    • 2017
  • $SnO_2$ was electrodeposited on nodule-type Cu foil at varing current density and electrodeposition time. Unlike the previous research results, when the anodic current is applied, the $SnO_2$ layer was not electrodeposited and the substrate is corroded. When the cathodic current was applied, the $SnO_2$ layer could be successfully deposited. At this time, the surface microstructure of the powdery type was observed, which showed similar crystallinity to amorphous and had a very large surface area. Crystallinity increased after low-temperature heat treatment at $250^{\circ}C$ or lower. As a result of evaluating the charge/discharge performances as an anode material for lithium ion battery, it was confirmed that the capacity of the heat treated $SnO_2$ was increased more than 2 times, but it still showed a limit point showing initial low coulombic efficiency and low cyclability. However, it was confirmed that the battery performances may be enhanced through optimizing the electrodeposition process and introducing post heat treatment.

지료조성에 따른 종이의 사이징 특성 (The Influence of Paper Stock Type on Characteristics of Sizing)

  • 정상진;김봉용
    • 펄프종이기술
    • /
    • 제37권2호
    • /
    • pp.11-20
    • /
    • 2005
  • This study was carried out to investigate the influence of paper stock type and heat treatment on sizing effect. Various types of pulps were used to make handsheets sized internally with AKD(alkyl ketene dimer) and externally with CMC(carboxyl methyl cellulose). Most of the handsheets were treated with heat by dry oven $(100^{\circ}C,\;30min)$ to evaluate the effect of heat treatment on sizing development. Internal sizing development of newsprint was very bad, but the effect of heat treatment was much higher than those of NBKP, BCTMP. In case of surface sizing, newsprint was more effective compared to the other pulps. Considering above mentioned results, it seems that internal sizing slows down water into paper by molecular diffusion much more than capillary penetration, but surface sizing slows down capillary penetration. With regard to density, a higher thickness sheets showed high heat treatment effect on sizing, therefore it assumed that heat treatment effect on sizing had very close relationship with sheet density.

열확산에 의한 다이아몬드 박막의 표면연마에 관한 연구 (A Study on the Surface Polishing of Diamond Thin Films by Thermal Diffusion)

  • 배문기;김태규
    • 열처리공학회지
    • /
    • 제34권2호
    • /
    • pp.75-80
    • /
    • 2021
  • The crystal grains of polycrystalline diamond vary depending on deposition conditions and growth thickness. The diamond thin film deposited by the CVD method has a very rough growth surface. On average, the surface roughness of a diamond thin film deposited by CVD is in the range of 1-100 um. However, the high surface roughness of diamond is unsuitable for application in industrial applications, so the surface roughness must be lowered. As the surface roughness decreases, the scattering of incident light is reduced, the heat conduction is improved, the mechanical surface friction coefficient can be lowered, and the transmittance can also be improved. In addition, diamond-coated cutting tools have the advantage of enabling ultra-precise machining. In this study, the surface roughness of diamond was improved by thermal diffusion reaction between diamond carbon atoms and ferrous metals at high temperature for diamond thin films deposited by MPCVD.