Laser welding can be divided by the different methods of laser output energy pulse laser welding and laser welding continuously (
Including high frequency pulse continuous welding)
By focusing on the spot after power density can be divided into different fusion welding and welding.
Fusion welding is in laser power density is not high on the spot, the surface of metal materials in the heating does not exceed its boiling point.
Absorbed by laser can change into heat, the workpiece melting of heat transfer through its penetration contour approximation for hemispherical.
This kind of fusion welding heat transfer process is similar to the melt arc welding.
Hole welding is when the laser power density on the spot is big enough, the metal under the irradiation of laser rapid heating, the surface temperature rise in a very short time to the boiling point, metal gasification.
Metal vapor leave the surface of molten pool at a certain speed.
An additional pressure reaction in molten metal, make its dent, under the effect of laser speckle generates a small pit.
As the heating process, the laser can be directly into the bottom to form a slender hole.
When the recoil of metal vapor pressure and liquid metal surface tension and gravity balance, holes not to continue further.
When light power density and big, throughout the thickness, the holes will form through the weld (
Or solder joints)
In continuous laser welding, the holes along the direction of welding with beam relative to the workpiece.
Metal melt at the front holes to bypass the holes after the flow to the rear, condensation formation of weld.
Plasma cloud in the process of laser welding under the condition of high power density in laser welding, can be found: laser and metal, metal evaporation is extremely intense, metal steam escape holes are red, and over the molten pool on the surface of the metal has a blue plasma cloud, it is accompanied by holes.
Due to the generation of plasma cloud with laser power density, the weld metal properties, shielding gas, etc.
And the adverse effects on the welding process, will be reduced for metal surface laser energy, welding penetration decreases, and broadening of weld surface, welding process is not stable.
The welding process methods overcome the influence of plasma cloud is through the nozzle of the molten pool surface of inert gas, can make use of the machinery of the gas blowing force expulsion of plasma cloud above make it deviates from the molten pool.
Still can use the low temperature gas to lower the temperature of the molten pool above high temperature gas, inhibit plasma cloud high temperature conditions.
Also can use high-frequency pulsed laser welding, make each laser pulse heating time is less than the more the ion cloud formation time (
, the plasma cloud is not generated welding heat is over.
Also can use high speed welding or call Duan Bo long laser welding, to reduce the intrusion of plasma cloud on welding process also have certain effect.
There are places to plasma cloud of equipment, including control host and described with control host through electrical connection induction coil, induction coil is located in plasma cloud is stated above, the host control induction coil is used for quick removal of the alternating magnetic field of plasma cloud.
Laser welding and cutting unfavorable use long-focus focus lens.
That is to say, on the focal plane of the beam diameter d and lens focal length and the beam divergence Angle theta (f
d = fθ)
, when the laser welding and cutting, in order to obtain a high enough power density, generally do not allow the beam divergence Angle is too large, also do not use the long focal length focus lens.
In colleges and universities should not be used in welding laser welding method.
Because of laser welding heat conduction, by laser energy to the workpiece internal transfer, laser can utilization rate is low, the welding speed is slow, shallow depth of molten, thick plate welding workpiece.
Characteristics of deep penetration laser to generate holes into the laser through the plasma and hole wall of multiple reflection and almost completely absorbed, high energy utilization rate, weld penetration, welding speed is fast, is a high efficient welding method, suitable for thick plate welding and the effect of the small holes of the thin plate welding.
To be on the safe side, at the entrance of the laser welding area should hang up the corresponding warning marks.
The laser beam transmission route request is higher than the height of and transmitted in the closed pipeline.
When open the laser or the pulse capacitor charging, to give sound and light warning.
In laser work, avoid eye and skin by direct laser radiation or diffuse light, conditional work site should be closed, only have observation hole, observation hole with a damping device, operation personnel outside the closed hood or remote control.
The workplace should be equipped with ventilation and fire safety devices, etc.
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Metal laser welding equipment 】
Suitable for all kinds of complex welding, the welding of different equipment and 1 mm thick seam welding;
Multi-channel fiber optic mode, welding transfer at the same time;
Mould laser welding equipment 】
Applicable mould industrialized, used for precision mold repair, such as digital products, mobile phones, toys, automobile, motorcycle, mold and other mold manufacturing and molding industry.
Gold and silver jewelry laser welding 】
Mainly used in jewelry, such as electronics, communications, handicrafts and other industries;
Large laser welding 】
Application in automobile body covering parts of compound, such as car door, side wai, window, floor, warehouse, the warehouse before, trunk lid.
Automatic laser welding machine 】
Using numerical control software by moving or rotating workpiece computer control of mechanical system, so as to realize automatic welding 【
The laser spot welder 】
Can be used for jewelry, watches and clocks hairspring, integrated circuit lead all kinds of small, precise welding of heat sensitive parts of the
YAG laser welding machine 】
High compactness, and strong weld, precise control, high power density, deep and narrow welds, welding seam and beautiful characteristics of laser welding equipment more laser welding laser welding machine