Laser Welding / Micro Welding
Laser beam welding (LBW) is a welding technique used to join multiple pieces of metal through the use of a laser. The beam provides a concentrated heat source, allowing for narrow, deep welds and high welding rates. The process is frequently used in high, medium and low volume applications, such as in the Medical, Aerospace and Automotive industry.
Micro Welding is the name given to the process that has evolved from traditional TIG welding (or more recently termed GTAW), using the technology of electric current being applied to the work piece to generate heat at the point of the arc gap. At the point of the arc gap, a molten pool is established and the filler rod is introduced into the molten pool.
The difference between traditional TIG and micro welding is that micro welding is done at extremely low amperage (usually less than 10 amps) in combination with fine control of the amperage range, along with the aid of a high-powered (10X-20X or more) microscope. In the micro welding process, the technician performing the weld repair – in combination with the welding equipment controls and the weld wire selection – is absolutely critical to the end result.
Laser welding uses light energy to rapidly heat the weld zone, melting the filler rod along with the adjacent point of metal joining. The light energy intensity is controlled by beam size, voltage, pulse width, singularly or is repeated at variably timed intervals. Because an independent high intensity light source is used, no current flows through the workpiece. There are no electrical connections or current polarity effects to the weld or to the workpiece with laser welding.
With the laser process there is no heat generated in the workpiece by electrical current flow or resistance to flow. Because the laser beam is used to melt the base material and the filler rod, the process becomes a line of sight as well as focal point limited process. Microscopic magnification, similar to micro welding, also is used in the laser welding process.