Application fields of Laser Cladding Technology|Laser cladding machines

Laser cladding is a kind of surface modification technology. First, use relevant instruments, such as spectrum analyzer, to scan the damaged part of the matrix to detect the constituent elements of the matrix material. Then, the repair and modification schemes are obtained, and the cladding materials are proportioned. Then, the cladding material is added to the surface of the substrate, and the laser energy is used to blend the cladding material into the substrate to form a cladding layer with the characteristics of wear resistance, corrosion resistance, heat resistance, oxidation resistance and electrical characteristics, so as to achieve basic repair or surface modification.
Laser cladding technology not only repairs and improves the surface characteristics of the substrate, but also saves a lot of valuable elements (experimental data show that compared with the new one, laser cladding can save 50% of the cost and reduce CO2 emission by more than 80%). Compared with surfacing, spray painting and electroplating, laser cladding has the characteristics of small dilution, compact structure, combination number between coating and substrate, more suitable cladding materials, large variation of particle size and content, so the application prospect of laser cladding technology is very wide.
The application fields of laser cladding repair include metallurgy, electric power, petroleum, chemical industry, shipbuilding, locomotive, coal machine, automobile and other pillar industries of national economy. According to the working conditions of different equipment, laser surface remanufacturing (cladding repair, additive manufacturing) mainly improves the wear resistance, corrosion resistance, high temperature resistance, oxidation resistance and other properties of metal parts, which can not only restore the failed parts, but also significantly prolong the service life of new parts.
Laser cladding machines.

Advantages of laser cladding technology | laser cladding machine

Laser surface remanufacturing (cladding repair and additive manufacturing) uses high-energy laser as heat source and alloy powder as cladding material. The alloy powder acts on the workpiece surface synchronously by laser irradiation to form a molten pool, and then rapidly solidifies to form a dense, uniform and thickness controllable metallurgical bonding layer. The cladding layer has special physical, chemical and mechanical properties that can be modulated, So as to repair the surface size of the workpiece, strengthen and extend the service life. Laser cladding machine
Advantages of Technology
1) High performance cladding layer can be selectively prepared on cheap and easy to process substrate surface, and the composition and properties of cladding layer are rarely diluted by the matrix material composition.
2) When the cooling rate is as high as 10 ＾ 6 ℃ / s, the microstructure of the cladding layer is finer, more compact, higher hardness, better wear resistance and corrosion resistance.
3) Laser processing is flexible and convenient to process parts (groove, inner hole wall, etc.) which are difficult to be processed by conventional methods. The movement precision is controllable and it is convenient to process complex contour surface. Selective accurate cladding repair can be realized with less subsequent processing.
4) Small heat affected zone, small deformation, dilution ratio ≤ 5%.
5) The thickness and shape of the cladding layer can be controlled accurately according to the requirements of working conditions, which can be combined with the base metal metallurgy.
6) The process is controllable, easy to realize automation, no pollution to the environment, low noise and comfortable working conditions.
7) It provides a new way for remanufacturing waste parts and prolonging their service life.

Advantages of laser quenching technology.

Laser quenching technology is a kind of surface heat treatment technology that uses a laser beam to heat the metal surface at a very fast rate to carry out impact quenching. It can also carry out surface layer fine grain strengthening solution. So what are the advantages of using laser quenching?

Compared with other basic quenching methods, laser quenching technology has the following advantages:

1. The high-precision hard bottom layer of high quality can be obtained. The strength is 15%-20% higher than the basic quenching. After quenching, the wear resistance of pig iron can be increased by 3-4 times, and the quenched deep layer can be accurately manipulated.

2. Only use partial and thin surface heating at the key parts of the work, and the input product has less heat generation, and the effect of environmental protection and energy saving is very good.

3. The heat treatment process has small deformation and no mechanical equipment deformation. It is suitable for high-precision parts and can be used as the final solution process for raw materials and parts. It is because the laser power is high and the effective time with a certain point on the part is very short, so the thermal deformation zone and the overall change of the part are small. This advantage is especially prominent for long product workpieces and thick-walled product workpieces.
4. Because the light directly shines on the product workpiece, it belongs to non-touch heating and over-temperature protection quenching, so this technicality is a clean heat treatment process.

5. Good production and processing softness and wide range of use. It can use the flexible light guide system software to freely direct the laser to solve the position, and then it can easily solve the difficult-to-produce and process areas such as deep holes, internal threads, buried holes, and concave grooves and some areas with very small indoor space.

6. There is no significant mechanical equipment interaction force and special tool loss, low noise, low environmental pollution, pollution-free treatment methods, and good labor standards.

7. The processing technology cycle time is short, the production efficiency is high, and the production is low-cost. The entire processing technology can be operated by an electronic computer. The level of automation technology is high. It can be included in the automatic production line to facilitate mass production.
Choosing laser hardening technology can not only obtain high-precision hard underlayer, but also reduce environmental pollution to the natural environment. It is very critical. Many basic quenching technologies have relatively large environmental pollution to the natural environment, and the noise is also large, causing irreversible adverse effects.

What are the quality advantages of laser quenching?

Laser quenching is a quenching technique that uses laser to heat the surface of the raw material above the change point, thereby hardening the surface of the raw material. So what quality advantages and technical characteristics does it have?

1. Quality advantages

Laser quenching has high power, faster cooling speed, and no cooling materials such as water or oil. It is a clean and rapid quenching process. Compared with the processing technology of induction hardening, flame quenching and nitriding quenching, the laser quenching hardened layer is symmetrical, high in strength (generally 1-3HRC higher than induction hardening), the deformation of the workpiece is small, and the deep heating layer and heating motion track are very easy to manipulate , It is convenient to complete the automation technology. It is not necessary to design the relative magnetic induction electromagnetic coil based on different parts specifications like induction hardening. The production and processing of large and medium-sized parts does not have to be subject to the limitation of the furnace specifications during the organic chemical heat treatment process such as nitriding and quenching. Therefore, in many industrial production industries, traditional handicrafts such as induction hardening and organic chemical heat treatment are gradually replaced. The most important thing is that the deformation of the left and right workpieces before and after laser quenching can basically be ignored, so it is very suitable for solving the surface of high-precision parts.

2. Technical characteristics

The main parameters of the deep layer of the laser hardened layer are in accordance with the components, specifications and appearances of the parts and the laser processing technology, and their main parameters are generally in the middle of the range of 0.3 to 2.0 mm. The shaft journals of large and medium-sized transmission gears and the motor shafts of large and medium-sized shaft parts are quenched. The surface roughness basis will not change, and the requirements of specific working conditions can be considered without post-machining and manufacturing.

Laser melting and quenching technology is the use of laser beams to heat the surface of the sheet above the melting temperature. Because of the heat transfer and cooling inside the sheet, the surface of the molten layer is rapidly cooled and the crystals are condensed. The obtained fusion quenching mechanism is very high-density, and the mechanisms along the deep layer are the fusion-condensation layer, the changed hard bottom layer, the thermally hazardous area and the plate. The laser melting layer is deeper than the laser hardened layer, the intensity is higher, and the wear resistance is stronger. The deficiency of this technology depends on the surface roughness of the workpiece surface suffering a certain level of damage, and generally must be repaired after machining. In order to reduce laser melting. To solve the surface roughness of the surface of the parts afterwards, reduce the output afterwards, and configure professional laser fusion quenching architectural coatings, which can greatly reduce the surface roughness of the fused layer. Nowadays, the hot-rolled strip steel, guide and guard and other workpieces of various raw materials in the industry where laser melting is carried out, the surface roughness has already been close to the level of laser quenching. The above-mentioned professional knowledge on the quality and technical aspects of laser hardening will be helpful to many interested people.

What are the advantages of laser cladding?

I believe everyone is familiar with the laser cladding equipment. It is a new surface modification technology that adds cladding materials to the surface of the substrate, and then melts the surface of the high-energy density laser, and has a surface on the surface of the base layer. Also metallurgical filling equipment. So what characteristics does it have? Let’s take a look.

Traditional solid-state lasers are usually pumped by high-power gas discharge lamps, with a pumping efficiency of about 3% to 6%. The large amount of energy emitted by the pump lamp is converted into heat energy, which not only causes the solid-state laser to adopt a bulky cooling system, but also causes the thermal lens effect that cannot be eliminated by the working material, thereby degrading the beam quality. And the life of the pump lamp is about 400 hours, so the operator needs to spend a lot of time to change the lamp frequently. If the system is interrupted, the efficiency of the automated production line will be greatly reduced. Compared with traditional lamp-pumped lasers, solid-state lasers (fiber lasers, disc lasers, diode lasers) have the following advantages:

1. High conversion efficiency: Because the emission wavelength of the semiconductor laser matches the absorption peak of the solid laser working material, and the pump light mode matches the laser oscillation mode, the light conversion efficiency is very high, reaching more than 50%. The efficiency of the whole machine can also be comparable to that of a carbon dioxide laser, which is an order of magnitude higher than that of a lamp-pumped solid-state laser, so the diode-pumped laser is small in size, light in weight and compact in structure.
2. Reliable performance and long life: The life of laser diode is much longer than flash lamp, up to 15,000 hours. The pump light has good energy stability, which is an order of magnitude better than flash lamp pumping. Its performance is reliable. It is a fully solidified device. It is a laser that does not require maintenance until now, and is especially suitable for large-scale production lines.

3. Good output beam quality: Due to the high conversion efficiency of the diode pumped laser, the thermal lens effect of the laser working material is reduced, and the output beam quality of the laser is greatly improved, resulting in the laser beam quality approaching the limit.

4. Fast speed, large depth, no deformation, no slag inclusion in the cladding layer, fine molten pool without pores.
　　
5. It can work at room temperature or under special conditions. For example, the beam will not be deflected after the laser passes through the magnetic field, and it can be used even in a vacuum. It is cladding through glass and transparent materials.

6. Thin-walled laser cladding can be performed, and the substrate has no deformation.

If the cladding materials include powder and base materials, which are highly reflective materials, fiber lasers and diode lasers are not suitable due to their own design characteristics. The disc laser is more suitable for welding (including cladding) and cutting materials with relatively high reflectivity.

Principle of laser cladding process equipment

Laser cladding, as the name suggests, is a new type of surface modification material technology. According to the method of adding cladding materials on the surface of the substrate, and then using all the machinery and equipment such as higher energy relative density to fuse, the production is completed. Technical craftsmanship.

Cladding process:

Laser cladding can be divided into two types according to the method of providing cladding materials, namely, preset laser cladding and synchronous laser cladding.

The preset laser cladding is to place the cladding material on the cladding position on the surface of the substrate in advance, and then use a laser irradiance scanner to melt, and the cladding material is added in the form of powder, wire, and plate. It is more common in powder form.

Synchronous laser cladding is to send the cladding material to the laser, so that the feeding and cladding are performed separately. The key to the cladding material is also to feed it in powder form. Of course, some people choose cables or boards to carry out synchronous feeding.

The key production process of preset laser cladding: first, the substrate cladding surface preparation treatment, and then preset the cladding material, then heat, laser fusion, and finally heat treatment process.

The key production process of synchronous laser cladding: first, the surface of the substrate cladding is prepared, then the material is fed for laser melting, and finally the heat treatment process is performed.

Laser principle:

The laser cladding mechanical equipment is composed of laser, refrigeration generator set, powder feeding organization, production and processing console, etc. The laser uses a solid-state laser and a common CO2 laser. Among them, CO2 lasers are the most widely used lasers with the largest number of types. They are used in the automobile industry, steel industry, shipbuilding industry, airlines and aerospace industry, motor industry production, mechanical engineering, steel industry, laser cutting processing of metal materials, etc. Widely used in the industry. It accounts for about 40% of the world’s total industrial production laser sales, and even 70% in North America. The laser has the following characteristics:

1. High output power. CO2 laser is one of the lasers with the highest level of power at this stage, and its large continuous power reaches several hundred thousand watts.

2. High efficiency. The photoelectric conversion rate is over 30%, which is much higher than other production and processing lasers.

3. High light quality. The use method is good, the use rate in related industries is high, and the line width is relatively stable in work use.