Laser welding machine welding technology and advantages
Laser welding and laser brazing are two standard joint processes in hot joint methods.So what are the advantages of laser in laser welding technology?
Compared with traditional arc welding technology, laser beam joint has many advantages:
1. Selective energy applications in small areas: thermal stress reduction and thermal shock zone reduction with very low distortion
2. Narrow slit, smooth surface: reduce or even eliminate reprocessing
3. Combination of high strength and low welding volume: welding parts can withstand bending or hydraulic forming
4. Easy integration: it can be combined with other production operations, such as straightening or bending
5. Just make sure the seam is tight on one side
6. High processing speed reduces processing time
7. Applicable to automation technology
8. Good program control: machine tool control and sensor system detect process parameters to ensure quality
9. The laser beam can generate welding points without touching the surface of the workpiece or applying any force
Heat conduction welding
In heat conduction welding, laser beams melt matching parts along a common joint, and the melted material flows together and solidifies, producing a smooth circular weld that requires no additional grinding or polishing.The depth of heat conduction welding varies from tens of millimeters to one millimeter.The thermal conductivity of the metal limits the maximum depth of the weld, and the width of the weld is always greater than the depth of the weld.
Deep fusion welding requires a very high power density of about 1 MW/cm2.When a laser beam melts the metal, it produces steam, which exerts pressure on the molten metal and partially replaces it.At the same time, the material continues to melt, creating a deep, narrow, steam-filled hole called the pinhole effect.As the laser beam moves along the weld, the hole edge, in the molten metal cycle consolidates and holes, producing a deep, narrow, uniform weld internal structure that may be 10 times the weld width,25 mm or deeper.
Active and protective gases
In the welding process, the active gas and protective gas play an auxiliary role to the laser beam.CO2 laser welding adopts active gas to prevent the formation of plasma cloud on the workpiece surface from blocking laser beam.
Shielding gas is used to protect the welded surface from surrounding air and the flow of shielding gas to the workpiece is non-turbulent (laminar).
Filling material is usually added to the place to be joined in the form of silk or powder.It has the following functions:
1. Fill gaps that are too wide or irregular, reducing the amount of work required to prepare joints.
2. Add fillers in the form of certain components to the molten metal to change the welding adaptability, strength, durability and corrosion resistance of the material.
Composite welding technique
Composite welding technology refers to the process of laser welding combined with other welding methods.Compatible processes are MIG(inert gas welding) or MAG(active gas welding), TIG(tungsten inert gas welding) or plasma welding.The composite welding technology is faster and less deformed than single MIG welding.
Laser brazing is where matching parts are joined together with a filler material or filler metal.The melting temperature of solder is lower than the melting temperature of base metal.When brazing, only solder is melted and only suitable parts are heated.Solder melts into the gaps between parts and binds to the workpiece surface (diffusion bonding).