Principles of welding robot laser processing
Welding robot laser processing uses a focused laser beam as a heat source to bombard the workpiece, melting metal or non-metal workpieces to form small holes, aligning, connecting, cladding and other processing methods. The microscopic process is a quantum process, and the macroscopic manifestation is reflection, absorption, heating, melting, vaporization and other phenomena.
Under the laser beam of different power density, the surface area of the material undergoes various changes, these changes include surface temperature increase, melting, vaporization, formation of small holes, and the generation of photo-induced plasma.
Laser power density is less than orders of magnitude
When the laser power density is less than an order of magnitude, the absorption of laser energy by the metal only causes the surface temperature of the material to rise, but the solid phase remains unchanged. It is mainly used for surface heat treatment, phase change hardening or brazing of parts. When the laser power density is in the order of magnitude, heat conduction heating will occur, and the surface of the material will melt. It is mainly used for metal surface remelting, alloying, cladding and heat conduction welding (such as thin plate high-speed welding and precision spot welding, etc.).
Laser power density reaches orders of magnitude
When the laser power density reaches an order of magnitude, the surface of the material is irradiated by the laser beam, and the heating temperature of the laser heat source reaches the boiling point of the metal, forming a plasma vapor and violently vaporizing. Under the pressure of vaporization expansion, the liquid surface dents down to form a deep Melt the small holes; at the same time, the metal vapor is ionized under the action of the laser beam to produce photo-induced plasma. This stage is mainly used for laser beam deep penetration welding, cutting and drilling.
Laser beam power density is greater than orders of magnitude
When the power density of the laser beam is greater than an order of magnitude, the photo-induced plasma will propagate against the incident direction of the laser beam, forming a plasma cloud, and the phenomenon of shielding the laser by the plasma will occur. This stage is only applicable to the use of pulsed laser for drilling , Impact hardening and other processing.