• 제목/요약/키워드: Electrochemical Characteristics

검색결과 1,471건 처리시간 0.024초

NaBr 및 NaF 용액에 대한 Sn-3.0Ag-0.5Cu 솔더 합금의 Electrochemical Migration 특성 (Electrochemical Migration Characteristics of Sn-3.0Ag-0.5Cu Solder Alloy in NaBr and NaF Solutions)

  • 정자영;장은정;유영란;이신복;김영식;주영창;정태주;이규환;박영배
    • Journal of Welding and Joining
    • /
    • 제25권3호
    • /
    • pp.57-63
    • /
    • 2007
  • Electrochemical migration characteristics of Pb-free solder alloys are quantitatively correlated with corrosion characteristics in harsh environment conditions. In-situ water drop test and corrosion resistance test for Sn-3.0Ag-0.5Cu solder alloys were carried out in NaBr and NaF solutions to obtain the electrochemical migration lifetime and pitting potential, respectively. Sn-3.0Ag-0.5Cu solder alloy shows similar ionization and electrochemical migration behavior with pure Sn because of Ag and Cu do not migrate due to the formation of resistant intermetallic compounds inside solder itself. Electrochemical migration lifetime in NaBr is longer than in NaF, which seems to be closely related to higher pitting potential in NaBr than NaF solution. Therefore, it was revealed that electrochemical migration lifetime of Sn-3.0Ag-0.5Cu solder alloys showed good correlation to the corrosion resistance, and also the initial ionization step at anode side is believed to be the rate-determining step during electrochemical migration of Pb-free solders in these environments.

이종 알루미늄 합금의 로봇 미그 용접 시 용접재료에 따른 기계적 및 전기화학적 특성 평가 (Mechanical and electrochemical characteristics with welding materials in robotic MIG welding of dissimilar Al alloys)

  • 김성종;한민수;우용빈
    • Corrosion Science and Technology
    • /
    • 제12권5호
    • /
    • pp.245-252
    • /
    • 2013
  • In this study, mechanical and electrochemical characteristics with welding material in MIG welded with ROBOT for dissimilar Al alloys were investigated using various experiment methods. The MIG welding by ROBOT with ER5183 and ER5556 for the 5456-H116 and 6061-T6 Al alloy were carried out. The hardness of welding zone was lower than that of base metal. In electrochemical experiment, ER5183 welding material presented excellent characteristics. The yield strength and maximum tensile strength in welding with welding material of ER5183 presented lower value than those of ER5556. The elongation and time-to-fracture showed the opposite results.

Low Temperature Interface Modification: Electrochemical Dissolution Mechanism of Typical Iron and Nickel Base Alloys

  • Jiangwei Lu;Zhengyang Xu;Tianyu Geng
    • Journal of Electrochemical Science and Technology
    • /
    • 제15권2호
    • /
    • pp.220-241
    • /
    • 2024
  • Due to its unique advantages, electrochemical machining (ECM) is playing an increasingly significant role in the manufacture of difficult-to-machine materials. Most of the current ECM research is conducted at room temperature, with studies on ECM in a cryogenic environment not having been reported to date. This study is focused on the electrochemical dissolution characteristics of typical iron and nickel base alloys in NaNO3 solution at low temperature (-10℃). The polarization behaviors and passive film properties were studied by various electrochemical test methods. The results indicated that a higher voltage is required for decomposition and more pronounced pitting of their structures occurs in the passive zone in a cryogenic environment. A more in-depth study of the composition and structure of the passive films by X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy showed that the passive films of the alloys are modified at low temperature, and their capacitance characteristics are more prominent, which makes corrosion of the alloys more likely to occur uniformly. These modified passive films have a huge impact on the surface morphologies of the alloys, with non-uniform corrosion suppressed and an improvement in their surface finish, indicating that lowering the temperature improves the localization of ECM. Together with the cryogenic impact of electron energy state compression, the accuracy of ECM can be further improved.