Effect Of TiC On The Structure And Properties Of Laser Cladding Fe-based Alloy Coating

Laser cladding knives have been designated as the 'fifth generation of high-end knives',which is based on the concept of "good steel on the blade".The laser coating technology is used to apply a layer of high performance material to the blade surface of the knife to improve the wear and corrosion resistance of the blade,which is crucial to the evaluation of high-end kitchen knives(sharpness and durability).In this paper,304 stainless steel with the same material as kitchen knife is used as the base material to discuss the composition optimization and high precision molding process control of the special stainless steel powder for laser cladding knife.Based on orthogonal experiments to optimise the process parameters,TiC was added to enhance the wear and corrosion resistance of the clad layer.The focus was on investigating the relationship between the TiC addition amount,TiC particle size and the microstructure and wear and corrosion resistance of the clad layer.The relevant findings of the study are as follows.1.On the basis of controlling a single variable,orthogonal experiments were designed to determine the optimum process parameters for the powder coating of stainless steel for laser clad knives using the extreme difference method: laser power P13(KW),scanning speed V13(mm/s),powder feeding speed Vs13(g/min)and protective gas G12(MPa).2.Using the optimized process,prepare ceramic-metal matrix composite coatings containing 0%,5%,15%,25%,and 35% TiC,respectively,and study the amount of TiC added and the macro morphology,microstructure and properties of the cladding layer Relationship.The analysis shows that the structure of the iron-based alloy coating near the fusion line is mainly cellular crystal;as the distance from the fusion line increases,the structure of the cladding layer changes from columnar dendrites to equiaxed crystals.When TiC is not added,the main phases of the cladding layer are ?-Fe,?-(Fe,Ni),Cr-Fe-Ni and Cr Fe4.When 5%TiC,a small amount of TiC appears in the phase.At 15%-35% TiC,the phase composition is ?-Fe,?-(Fe,Ni),Cr-Fe-Ni,Cr Fe4 and Cr Fe7C0.45,Cr2Fe14 C,Fe3Ni2,TiC.When the amount of TiC added is 25%,the overall wear and corrosion resistance of the coating is better.3.On the basis of controlling the amount of TiC(25%),prepare TiC ceramic-metal matrix composite coatings with particle sizes of 15-45?m,45-75?m,75-105?m,and greater than 105?m,and study the particle size of TiC and the cladding layer.The relationship between macroscopic morphology,microstructure and performance.The results show that different particle sizes have basically no effect on the phase composition of the cladding layer.With the increase of the TiC particle size,the holes and crack defects in the cladding layer increase significantly.The dendritic structure in the cladding layer changes from fine to coarse,and the existence of black hard particles in the cladding layer gradually transitions from regular shapes to petal-like,polygonal and other shapes.The hard reinforcement particles formed by TiC with different particle diameters are more evenly distributed at 15-45?m,and the structure of the cladding layer is dense.The average hardness value in this particle size section is the highest,the amount of wear is the smallest,and the corrosion resistance is the best.The amount of TiC added is 25%,the particle size is 15-45 ?m,and the best performance is available.