Laser Beam Welding: Part One

요약:

Laser beam welding effectively uses energy from the laser beam itself to melt and join the same metals and also dissimilar metals to one another.
Some of the main advantages of laser beam welding are its rapid speed (up to 10 times faster than TIG welding), highly repeatable results, accuracy to allow for problematic deep narrow welds to be completed.

Laser beam welding is a fusion joining process that uses the energy from a laser beam to melt and subsequently crystallize a metal, resulting in a bond between parts. Laser beam welding can be successfully used to join many metals to themselves as well as to dissimilar metals. Main applications are related to welding steels, titanium, and nickel alloys.

When the laser beam makes contact with the metal(s), the energy is converted from light to thermal energy. Concentrating the laser on an area as small as 0.2 mm in diameter, the heating effect is magnified greatly. Providing the laser power is calibrated correctly, the weld area (where the two pieces meet) will melt and then crystallize, fusing the parts together. If the laser is too powerful the laser may heat the material beyond the point of vaporization and simply slice straight through it. It is therefore important that the laser beam be set up to operate for the specific application being considered.

The action of the laser beam that leads to the formation of a welding cord can be decomposed following the stages below (Figure 1):

  • the material is first heated by conduction;
  • the absorbed energy provokes, by superficial penetration, the melting of the alloy on the impact surface;
  • the operation takes place by emitting a metallic vapour which develops at the centre of the impact point. The material partly absorbs and diffuses the energy of the beam;
  • the vapour pressure increases and dispels the melting alloy to the periphery of the beam and upwards. A narrow (capillary) shaft is created, which then propagates through the material. This shaft, whose diameter is barely greater than that of the beam, is physically occupied by metallic vapour plasma. Its walls are coated with a film of melting metal maintained by capillarity;
  • the melting metal is finally sent backwards and closes the capillary that forms the welding cord (Figure 2).



Figure 1: Stages of welding cord formation



Figure 2: Welding cord by continue welding

Advantages of laser beam welding

High productivity (nearly 10 times faster than TIG).

  • Low heat input and therefore low distortion.
  • Ease of automation for repeatability.
  • No need for filler wire, thus reducing costs.
  • Similar and dissimilar metals can be welded easily.
  • Clean weld joints.
  • Deep and narrow welds can be done.
  • Absence of distortion in welds created.
  • Minimal heat affected zones in welds created.
  • Excellent metallurgical quality will be established in welds.
  • Ability to weld smaller, thinner components.
  • Increased travel speeds.
  • Non-contact welding.

Disadvantages of Laser Welding

  • Slow welding speeds (25-250 mm/min).
  • Rapid cooling rate cause problems such as cracking in high carbon steels.
  • High equipment costs.
  • Very high reflectivity of a laser beam by the metal surface.
  • High equipment cost.
  • Require precise joint and laser beam alignment.

Applications of Laser Welding

Used in electronics industry for applications such as connecting wire leads to small electronic components, to weld medical equipment, transmission components in automobiles and in cladding process.

기술 자료 검색

검색할 어구를 입력하십시오:

검색 범위

본문
키워드

머릿글
요약

Total Materia는 용접용으로 적합한 다양한 국가와 규격 내 수천개의 재질에 대한 정보를 포함하고 있습니다.

재질의 화학적 조성, 기계적 특성, 물리적 특성, 탄소 등가 데이터와 용접용으로 재질 이용 시 필요한 정보 등의 전체적인 특성 정보들을 어디서든 검토하실 수 있습니다.

고급 검색을 이용하여, 검색 조건의 재질 리스트에서 '용접 필러 재료'를 선택합니다. 검색 범위 좀 더 줄이기를 원하신다면 국가/규격과 같은 다른 조건을 지정할 수 있습니다.

검색 버튼을 클릭합니다.


선택된 정보에 부합하는 일련의 재질이 검색됩니다.


결과 리스트에서 재질을 선택하시면, 일련의 규격 사양 소그룹이 나타납니다.

여기에서 선택한 재질의 특정 특성 데이터를 검토하실 수도 있고, 강력한 상호 참조 표를 이용하여 유사 재질이나 등가 재질을 검토하는 것 또한 가능합니다.


자세한 특성 데이터를 보시려면 특성 데이터 링크를 클릭하세요.


Total Materia 데이터베이스를 사용해 보실 수 있는 기회가 있습니다. 저희는 Total Materia 무료 체험을 통해 150,000명 이상의 사용자가 이용하고 있는 커뮤니티로 귀하를 초대합니다.