In general cases heat is required to fuse the metals for any types of welding, in laser beam welding process the heat is obtained from the application of a concentrated coherent light beam which striking upon the weld metal and melt the metal, such this weld joint is obtained, this welding process is called laser welding.
In laser beam, the lights are coherent, i.e. light rays are identical and parallel.
The laser device is generates the concentrating light wave into narrowly and gets the highly intense beam which can imparts tremendous amount of heat energy on a small area, this heat energy can fuse the metals, which we are using for welding purpose.
Principle diagram of laser welding
Principle of laser beam welding
A laser beam is produced inside of the Ruby Crystal. The Ruby Crystal is made of aluminium oxide with chromium dispersed throughout it. Which is forming about 1/2000 of crystal, this less than natural ruby. Silver coated mirrors are fitted internally in the both side of crystal. The one side of mirror has a tiny hole, a beam is come out through this hole.
A flash tube is placed around the Ruby Crystal, which is filled with xenon inert gas. The flash is specially designed such as which is made flash rate about thousands flashes per seconds. The electrical energy is converted into light energy, this is worked by flash tube.
The capacitor is provided for storage the electrical energy and supply the high voltage to flash tube for performed appropriately.
The electrical energy discharged from capacitor and xenon transform the high energy into white flash light rate of 1/1000 per second.
The chromium atoms of Ruby Crystal are excited and pumped into high energy. Due to heat generating the some of this energy is lost. But some light energy reflected mirror to mirror and again chromium atoms are excited until loss their extra energy simultaneously to form a narrow beam of coherent light. Which is come out through the one end tiny hole of crystal’s mirror.
This narrow beam is focused by a optical focusing lens to produce a small intense of laser on the job.
Advantage of laser beam welding