Research Of The Laser Deposition Process And Performance Of The TiC Composite Layer On The Kitchen Knife Blade

The production of kitchen knife has a long history in China. However because of it’s poor quality and lower worth, the high-end kitchen knife market now is occupied by the foreign goods. According to the analysis, the foreign high-end kitchen knife blade has good wear resistance, corrosion resistance and toughness, therefore, the key to produce the high-end kitchen knife is improve the performance of the blade. Due to the advanced laser cladding processing technology has the adventages of high efficiency, stable, little pollution and small heat affected zone, the trend of the high-end kitchen knife production is to strengthen the kitchen knife blade by the laser cladding technology.In this paper, the 316L+Ti C alloy deposition layer was prepared along the blade surface by the coaxial powder feeded laser deposition system. The microstructure,distribution of alloy elements, microhardness, friction and wear performance of the cladding layer and the performance of the knife edge which was deposited were studied.The results show that with the increasing of deposition speed and laser power, the forming quality of the cladding layer become better first and then poor. With the increase of the shielding gas pressure, the forming quality become poor; With the increase of deposition speed, the thickness, deposition quantity and the dilution rate of cladding layer decrease; With the increase of laser power, the thickness, deposition quantity and the dilution rate increase; With the increase of shielding gas pressure, the thickness and the quantity decrease, but the dilution rate increase; The thickness,deposition quantity and dilution rate of the blade deposition layer is inversely proportional to the deposition rate, and is proportional to the laser power. The high quality forming of strengthen cladding layer on the blade is obtained at the best powder formula and the optimum process parameters. The average macro-hardness of the cladding layer is 62.68 HRC, which reaches the hardness needs of high-end cutting tools, and the dilution rate is 0.22. The section of blade layer formes three typical areas, namely the cladding area, the transition area and the matrix. The cladding layers contain a lot of TiC particles un-melt, and inlaying directly to the softening 316 L alloy matrix, which has the toughening buffer effect on TiC particles. The transition zone appears a small amount of grain coarsening phenomenon, but there is no obvious overheat structure. The grain internal mainly is lath martensite structure; The matrix is dense acicular martensite organization, and there are a small amount of particlesbetween the grain. The alloy elements spread each other at the interface between cladding layer, the flutuation rang of four elements content of Fe、Cr、Ti、C during the cladding layer is bigger; The microhardness of the cladding layer is between HV0.5690 and HV0.5900, the average microhardness is about HV0.5800, which is the 2.1 times that of the matrix. With the increase of the test force, the friction coefficient of blade deposition layer gradually decreases, and the process of wear is more and more smooth. Because the blade cladding layer has excellent antifriction performance,which is help to reduce the wastage of the blade in the process of using, and greatly prolong the service life of the kitchen knife; The initial sharpness、durability and blade corrosion resistance of the laser cladding knife achieves the European standard "excellent" level.