21 May 2017

Laser beam welding advantages disadvantages

Laser beam welding is a technique of welding which used to join multiple pieces of metal through the use of laser. It is frequently used in high volume applications using automation, such as in the automotive industries. Let us have a deep insight into the pros and cons of laser beam welding in this article.

Advantages of laser beam welding :

  • Welding of complicated joint geometry.
  • Precise working with the exact placing of the energy spot done in laser beam welding.
  • Low heat application, therefor minor changes in microstructure.
  • Low thermal distortion.
  • Cavity free welds.
  • Low post-weld operation time.
  • Large working distance is also possible. 
  • Heat input is close to the in a minimum required to fuse the weld metal, thus heat-affected zones are reduced and workpiece distortions are minimized.
  • Time for welding thick sections is reduced and the need for filler wires and elaborate joint preparations is eliminated by employing the single-pass laser welding procedures.
  • No electrodes are required.  
  • LBM being a non-contact process so distortions are minimized and tool wears are eliminated.
  • Welding in areas that are not easily accessible with other means of welding can be done by LBM.
  • The joining of small spaced components with tiny welds very easily because of a laser beam can focus on a small area.
  • Wide variety of materials including various combinations can be welded very easily.
  • Thin welds on small diameter wires are less susceptible to burn back than is the case with arc welding. 
  • Metals with dissimilar physical properties, such as electric resistance can also be welded by LBW.
  • No vacuum or X-Ray shielding is required. 
  • Welds magnetic materials also. 
  • Aspect ratios mean depth-to-width ratio of the order of 10:1 are attainable in LBM.
  • Faster welding rate.
  • No flux or filler metal required.
  • Single-pass two-sided welding. 
  • Shorter cycle and higher up times. 

Disadvantages of laser beam welding :

  • The welding equipment is expensive so the cost for this process is high.
  • If the filler material is necessary but in this process limited amount produced with the use of filler material so relatively expensive.
  • There are also a few post welding operations. 
  • Joints must be accurately positioned laterally under the beam.
  • The final position of the joint is accurately aligned with the beam impingement point.
  • The maximum joint thickness that can be welded by laser beam is somewhat limited. 
  • The materials have high thermal conductivity and reflectivity like Al and Cu alloys can affect the weldability with lasers. 
  • An appropriate plasma control device must be employed to ensure the weld reproducibility while performing moderate to high power laser welding. 
  • Lasers tend to have low energy conversion efficiency less than 10 percent. 
  • Some weld-porosity and brittleness can be expected, as a consequence of the rapid solidification characteristics of the LBM.