• Title/Summary/Keyword: Aluminum joining

Search Result 328, Processing Time 0.026 seconds

Theoretical background discussion on variable polarity arc welding of aluminum (가변 극성 알루미늄 아크 용접의 이론적 배경 고찰)

  • Cho, Jungho;Lee, Jungjae;Bae, Seunghwan;Lee, Yongki;Park, Kyungbae;Kim, Yongjun;Lee, Junkyung
    • Journal of Welding and Joining
    • /
    • v.33 no.2
    • /
    • pp.14-17
    • /
    • 2015
  • Cleaning effect is well known mechanism of oxide layer removal in DCEP polarity. It is also known that DCEN has higher heat input efficiency than DCEP in GTAW process. Based on these two renowned arc theories, conventional variable polarity arc for aluminum welding was set up to have minimum DCEP and maximum DCEN duty ratio to achieve the highest heat input efficiency and weldability increase. However, recent several variable polarity GTA research papers reported unexpected result of proportional relationship between DCEP duty ratio and heat input. The authors also observed the same result then suggested combination of tunneling effect and random walk of cathode spot to fill up the gap between experiment and conventional arc theory. In this research, suggested combinational work of tunneling effect and rapid cathode spot changing is applied to another unexpected phenomena of variable polarity aluminum arc welding. From previous research, it is reported that wider oxide removal range, narrower bead width and shallower penetration depth are observed in thin oxide layered aluminum compared to the case of thick oxide. This result was reported for the first time and it was hard to explain the reason at that time therefore the inference by the authors was hardly acceptable. However, the suggested combinational theory successfully explains the result of the previous report in logical way.

Resistance spot welding of aluminum alloys (알루미늄 합금의 저항 점용접)

  • 한용섭
    • Journal of Welding and Joining
    • /
    • v.8 no.2
    • /
    • pp.1-12
    • /
    • 1990
  • 본 고에서는 알루미늄 점용접시의 용접품질 및 용접봉 수명에 미치는 요소와 점용접부 설계방법에 대하여 간략히 설명하였다. 점 용접방법은 알루미늄 뿐만 아니라 steel의 박판용접에도 많이 사용되고 있으며, 특히 최근 공정자동화에 맞추어 가장 쉽게 자동화할 수 있는 용접 방법 중의 하나이다. 그러나 아직까지는 용접품질을 보증할 수 있는 비파괴 검사방법이 없기 때문에 새로운 비파괴 검사방법 개발 혹은 컴퓨터를 이용한 용접품질 추적방법에 대한 많은 연구가 요청된다. 한편 용접부 설계 관점에서는 조그만 단순 시편이 아닌 설계구조물을 이용한 용접강도 해석방법에 대한 연구가 미약하므로 이에 대한 많은 연구도 요청되고 있다.

  • PDF