Application status of laser cladding in agricultural machinery repair and strengthening

The market background China is one of the few agricultural countries in the world. With the accelerating pace of reform and opening up, China began to promote agricultural mechanization and automation development on a large scale. According to statistics, in 2000 our country agricultural mechanization degree already reached 48%. However, there is still a big gap between China and developed countries in terms of product reliability, safety, durability and adaptability due to the low level of agricultural mechanization manufacturing technology in China. In particular, the key parts of agricultural machinery directly affect its service life, such as rotary tillage knife, harvester cutter plate, ditcher and other key wear parts failure greatly increases the maintenance cost, but also seriously affect the efficiency of agricultural machinery; Now most of the maintenance of agricultural machinery is just a simple disassembly and replacement, not only increased the operating cost of agricultural machinery enterprises, but also hindered the popularization of agricultural mechanization in Our country. For the traditional agriculture which develops relatively slowly, the advanced laser technology is applied to the agricultural field, among which the most eye-catching is the laser cladding technology for the repair and strengthening of agricultural machinery. Laser cladding is a surface modification technology of substrate. Through the preset cladding path, using a laser irradiation in the surface layers of the cladding material and substrate laser through rapid melt into the molten pool, and then rapidly solidified into a layer of metallurgical bonding, low dilution degrees of cladding layer, which can carry on the in situ repair of mechanical parts, or improve the original on the surface of the substrate material wear-resisting, corrosion resistant, heat resistant, antioxidant and other properties of cladding process method. Compared with traditional processing technology, laser cladding technology has the following characteristics: Metallurgical bonding can be formed between cladding layer and matrix. The matrix is not easy to deform due to the small thermal influence; The dilution rate of cladding layer is low, saving expensive cladding material; The thickness of cladding layer can be controlled; It can repair specific parts of parts and other parts that are difficult to deal with. It is necessary to pretreat the surface of agricultural machinery parts before repairing them by cladding. Due to the harsh working environment of agricultural machinery, the surface of agricultural machinery parts often contains soil, oil, water, fertilizer, pesticide, rust, oxide layer, etc., so the repair of parts is more complicated than that of other fields. For parts of agricultural machinery, the general operation is to touch the soil farming parts to first wash the surface dirt, if the dirt on the damaged surface is firm, can use mechanical sandblasting method to clean, and the engine, rotating shaft and other parts are cleaned with detergent to remove the oil. Then the cladding surface is polished with sandpaper and cleaned with acetone, so as to avoid the defects caused by surface stains entering the cladding layer during laser cladding and affecting the quality and performance of the cladding layer. The main techniques of traditional agricultural machinery repair are heat treatment, chromizing and arc spraying, but they are difficult to meet the requirements of wear resistance, corrosion resistance and pollution-free agricultural machinery. With the development of laser cladding technology, the properties of cladding coatings are becoming more and more excellent. Therefore, scholars began to study the application of laser cladding technology in agricultural machinery repair and strengthening. Laser cladding technology can not only be used to repair damaged parts, but also can be used to enhance the performance of existing agricultural machinery parts. As early as in 2009, the researchers in our country has carried on the exploration to rotary tillage blade surface laser treatment, through the design of orthogonal test and extreme difference analysis, and found that influence the effect of substrate surface enhanced laser power > is the main, in turn, scanning speed > spot diameter, material after laser surface cladding, refine matrix was obvious, and formed in the cladding region many relatively small high carbon martensite, The microhardness is increased and the wear resistance of rotary blade is improved. After that, through the design optimization experiment, the extension effect of common heat treatment, laser heat treatment and laser cladding single surface modification technology on the service life of lawn mower blade is compared, and the results show that laser cladding is superior to the former two. Therefore, it is of great practical significance to explore advanced repair technology and performance improvement means for key parts of agricultural machinery to improve service performance and prolong service life of agricultural machinery.铜焊丝,Copper Welding Rods,铝焊丝,aluminium welding wire,镍焊条,Nickel electrode,药皮焊条,Flux Coated Brazing Welding Rods