The hottest laser cladding alloying technology

Laser cladding alloying technology

laser cladding technology is a process that uses laser beam to cladding a layer of materials with special properties on the surface of selected workpieces to improve the surface properties of workpieces. Laser cladding technology uses a laser beam to cladding a layer of materials with special properties on the surface of selected workpieces, so as to improve the workpiece surface, which can be used to measure the displacement of samples, and can also approximately replace the deformation of samples; Process for surface properties of some metal materials. Compared with the traditional spray welding or surfacing process, laser cladding technology has the following advantages:

(1) the energy density of laser beam is high, and laser cladding can be completed as long as less energy is injected. The parts have small heat affected zone and small deformation, so it is suitable for strengthening or repairing some high-precision parts or parts with strict deformation requirements, such as the surface strengthening treatment of finishing rolls

(2) the dilution ratio of laser cladding layer is low and can be accurately controlled. The composition and performance of cladding layer mainly depend on the composition of cladding material. Therefore, various materials with excellent properties can be used to modify the surface of the substrate. In particular, laser cladding technology can be used to repair some workpieces that cannot be achieved by conventional surfacing technology, such as turbine engine blades, roller spindles, motor spindles, etc

(3) the laser cladding layer has dense structure, few micro defects, metallurgical bonding between the cladding layer and the substrate, and high strength, so it can be used for surface strengthening and repair of parts under heavy load conditions, such as large rollers, large gears, large crankshafts and other parts

(4) the size and position of the laser cladding layer can be accurately controlled. A special light guide system is designed, which can laser process deep holes, inner holes, grooves, blind holes and other parts. Using some special light guide systems such as broadband scanning system, the width of a single laser cladding layer can reach 20~30mm, and the maximum thickness of each cladding can reach more than 3mm. The laser cladding of large area and large thickness on the workpiece surface can be realized through multi-channel lapping, which can meet the requirements of laser surface strengthening and repair of typical vulnerable parts such as rolls with different shapes and sizes

laser cladding process can be divided into preset coating method and synchronous feeding method according to different adding methods of materials. Generally, laser cladding is completed by adding alloy powder. Laser surface alloying is similar to the process of laser cladding, which changes the composition, microstructure and properties of the workpiece surface by adding alloying elements. However, the biggest difference between laser surface alloying and laser cladding is that the alloy elements added by the former are fully mixed with the substrate, and the two together determine the performance of the surface layer. Laser cladding mainly uses the properties of the added alloy powder, and the substrate has little contribution to the properties of the surface alloying layer. For a large number of vulnerable parts such as rolls, guides, conveying rolls, pinch rolls and cutting edges in the metallurgical industry, the biggest advantage of laser cladding and alloying technology is that the overall alloying of rolls into surface alloying has led to fundamental changes or cladding in the field of instruments and meters, which has greatly improved the service life of vulnerable parts such as rolls, while the increase in production costs is limited. Obviously, the design, selection and use of alloy powder are the key to the success of this technology

laser welding is one of the important aspects of the application of laser material processing technology. Its principle is to radiate high-intensity laser to the metal surface, and melt the metal to form welding through the interaction between laser and metal. Because of its unique advantages, it has been successfully applied to the precision welding of micro and small parts. The emergence of high-power CO2 and high-power YAG lasers has opened up a new field of laser welding, obtained deep penetration welding based on keyhole effect and building structure theory, and has been increasingly widely used in machinery, automobile, steel and other industrial sectors

compared with other welding technologies, the main advantages of laser welding are:

laser welding has fast speed, large depth and small deformation

it can weld at room temperature or under special conditions, and the welding equipment is simple. For example, when the laser passes through the electromagnetic field, the beam will not shift; Laser can weld in vacuum, air and some gas environment, and can weld through glass or materials transparent to the beam

after laser focusing, the power density is high. When welding workpiece with high-power laser, the depth width ratio can reach 5:1, and the maximum can reach 10:1

it can weld refractory materials such as titanium and quartz of steel strands, and can weld dissimilar materials with good results. For example, the diamond saw blade uses laser to weld the substrate (65Mn) with high-strength and super hard artificial diamond, which multiplies the service life and value of this saw blade

micro welding can be carried out. After focusing, the laser beam can obtain a very small spot and can be accurately positioned. It can be applied to the assembly and welding of micro and small components produced in large quantities. For example, due to the use of laser welding, the production efficiency is greatly improved, the heat affected zone is small, and the solder joint is pollution-free, which greatly improves the quality of welding

it can weld inaccessible parts, and implement non-contact long-distance welding, which has great flexibility. Especially in recent years, optical fiber transmission technology has been used in YAG laser processing technology, which makes laser welding technology more widely promoted and applied

laser beam is easy to realize beam splitting according to time and space, and can carry out multi beam simultaneous processing and multi station processing, which provides conditions for more precise welding

at present, the typical cold rolling process route in China's iron and steel industry is: converter smelting - refining outside the furnace - blooming - hot continuous rolling - Pickling - cold rolling - annealing - leveling - galvanizing (TIN) - finished products. In this typical cold rolling process, strip welding equipment is essential. During the operation, the first steel strip and the second steel strip must be welded to ensure the continuous operation of the production line. When the silicon steel strip is running, it needs to undergo multiple S-shaped bending deformation and bear a certain running tension, so it has high requirements for the performance and quality of the weld