Relationship between the keyhole laser welding and the plasma

Abstract

In this paper we investigated the behaviours of the laser beam keyhole welding with different laser beam sources, CO2 and a solid state Nd: YAG. We showed the differences between the types of laser welding, the geometry and method. Today the most used laser welding technology is the laser beam keyhole welding. In our research we investigated the heating effect of photons and the absorption method on the substrate surface. The photons can significantly absorbed better in case of 106 W/cm2 or more because of the plasma state in the welding material. The quality of the keyhole plasma depend on the free electrons of the materials and working medium. A theory of the creation of plasma phase and cloud were investigated. There is a difference working inside the metal vapour and working gas plasma cloud using CO2 and Nd: YAG. The solid state laser beam source shows better quality of the joint in keyhole welding.