Working principle, features and advantages of laser welding
- the working principle of laser welding machine
The laser welding machine uses a continuous high power density laser beam to irradiate the material, so that the material melts, vaporizes and forms small holes. The hole is like a black body. And the absorption rate of the laser beam is very high, which causes the temperature in the hole to rise rapidly. And the equilibrium temperature can reach about 2500℃. The heat travels around the hole wall, melting the surrounding material. Under the continuous irradiation of the high-energy laser beam, the gasification metal is continuously formed. Under the joint action of the pressure generated by metal gasification and the tension of liquid metal in the hole wall, a relatively stable state of small hole — molten metal — solid metal is formed from inside to outside. This relatively stable state moves as the weld joints.And the path they going through will leaves weld joint by condensation of liquid metal.
The features and advantages of laser welding machine
A.High aspect ratio: Because the molten metal is formed according to the cylindrical high temperature steam chamber, the weld formed is narrow and deep.
B. Low heat input: The laser beam energy density produced by the laser welder is very high. The temperature around the hole rises fast. The melting – condensation process occurs in a very short time. Greatly reduce the heat input to the workpiece, reducing the thermal deformation and thermal impact.
C.High density: Due to the existence of small holes in the laser welding beam, it not only can accelerate the gas overflow, but also it can properly stir the welding pool. So as to generate non-porosity and high density welds.
D. Solid welding: Ultra-high temperature generated by laser welding point can further remove the non-metallic structure of the material, reduce impurities or change its distribution in the material. Moreover, laser welding does not require electrodes or filler wires, which further reduces the contamination of the melting zone, enhances the strength and toughness of the weld, and even exceeds the performance of the parent metal.
E.Accurate control: The laser focus emitted by the laser welding machine is very small. So the welding joint can be positioned with high precision and the error is lower, so as to improve the welding accuracy and reduce the reprocessing cost.
F.Faster speed: Because the laser energy density produced by the laser welding machine is very high. The welding speed is very fast. Coupled with its very low thermal effect, the laser welder has a good welding effect for the titanium, alloy and other difficult welding metals.