Study On The Process And Microstructure And Properties Of Laser Cladding Ni60A/TC4 Layer On The Surface Of TC4 Alloy

TC4 alloy is very suitable for making high-end kitchen utensils,such as titanium alloy kitchen knives,due to its good biocompatibility,non-toxic health,corrosion resistance and light weight.However,the low hardness and poor surface wear resistance of TC4 alloy limit its cutting performance.Laser cladding technology is an important means of material surface strengthening,and has been widely researched and applied in different industries.The preparation of a surface modification layer with good corrosion resistance,high hardness and wear resistance on the surface of TC4 alloy by laser cladding technology is the basis for realizing TC4 alloy as a kitchen knife material.The key to preparing a cladding layer with good molding quality is the cladding process.Exploring the relationship between the microstructure of the cladding layer and its corresponding properties can provide a certain theoretical basis for guaranteeing the performance of the cladding layer.In this paper,Ni60A/TC4 laser cladding layers with different mass fraction ratios were prepared on the surface of TC4 alloy,and the optimal ratio was determined by observing the molding quality and testing the microhardness;Optimizing the cladding process parameters by orthogonal test,taking the molding quality,dilution rate,and microhardness as evaluation indicators,and calculating the best claddi ng process parameters by variance analysis;In order to further improve the performance of the cladding layer,composite cladding layers with WC and CeO ₂ were prepared using optimized process parameters,and the effects of different additions of WC and CeO₂ on the molding quality and performance of the cladding layer were analyzed.The research results show that the optimal ratio of base powder is70%Ni60A+30%TC4;the optimized cladding process parameters are:laser power 1200 W,scanning speed 3.5 mm/s,powder feeding speed 13 r/min;The cladding layer prepared by the optimized process is well formed,without defects such as cracks and pores.A good metallurgical bond is formed between the substrate and the cladding layer of Ni60A/TC4 with different mass fractions of WC;As the amount of WC increases,the unmelted WC particles in the cladding layer increase,and the peak intensity of newly formed Ti C,Ni₁₇W₃ and Ti WC₂ also increases;The microhardness of the cladding layer increases with the increase of WC a ddition;Adding more WC can improve the wear resistance of the cladding layer.When the WC addition is 12%,the wear resistance is the best,but the corrosion resistance decreases with the increase of WC addition.If the addition of WC continues to increase,it is not conducive to the preparation of corrosion-resistant and wear-resistant cladding layers on the surface of titanium alloy kitchen knives.The Ni60A/TC4 cladding layer with different mass fractions of CeO₂ is well bonded to the substrate.The addition of CeO₂ did not change the basic phase composition of the cladding layer,but it enhanced the diffraction peak of the ceramic phase in the cladding layer,and the effect was most significant when the addition amount was 0.3%.Within the research range,with the increase of CeO₂ addition,the structure of the cladding layer is first refined and then coarsened;the wear resistance of the cladding layer is improved;the corrosion resistance of the cladding layer is first increased and then slightly decreased.When the addition amount is0.3%,the microstructure is the smallest;the microhardness is the highest,the wear resistance is the best,and the corrosion resistance is improved the most.In summary,adding WC to Ni60A/TC4 mainly improves the hardnes s and wear resistance of the cladding layer,but the corrosion resistance decreases,which is not conducive to the preparation of a titanium alloy kitchen knife cladding layer with excellent corrosion resistance.After adding CeO₂,the cladding layer has excellent corrosion resistance,high hardness and wear resistance.