Microstructure And Properties Of AlCoCrFeNiTi_x High-Entropy Alloy Coatings Prepared By Laser Cladding Based On The Response Surface Methodology

The laser cladding technology was used to prepare the high entropy alloy cladding layer,to investigate the influence of the process parameters on the macroscopic morphology of the high entropy alloy cladding layer,to analyse the mechanism of the change in the molar ratio of titanium elements on the physical phase,microstructure and properties of the cladding layer,and then to explain the change in the macroscopic properties of the high entropy alloy cladding layer,to provide a theoretical basis for mould surface repair and remanufacturing,and to provide a reference for the application of laser cladding of high entropy alloy,and then to explain the change in the macroscopic properties of high entropy alloy,to provide a theoretical basis for mould surface repair and remanufacturing,and to provide a reference for the application of laser cladding of high entropy alloy technology and It is of some reference value for the application and prediction of performance analysis of laser clad high entropy alloys.In order to explore the laser cladding AlCoCrFeNiTi surface forming method.Firstly,based on the Box-Bohnken Design(BBD)response surface method,the mathematical model between the process parameters and the macroscopic morphology of the melt layer is established,and the coupling effects of laser power,scanning speed and powder feed voltage on the dilution rate,aspect ratio and melt area are investigated,and the NSGA-II genetic algorithm is used to optimise the dilution rate and aspect ratio as the minimum and the melt area as the maximum.The optimum process parameters for the cladding layer are 1770.60 W laser power,5.96 mm/s scanning speed and 23.26 V powder supply voltage,which enable effective control of the cladding layer formation quality.Secondly,on the premise of producing high-quality high-entropy alloy cladding layers by laser cladding,a first-principles calculation method based on the generalised density theory was used to calculate the properties of AlCoCrFeNiTi_xand the effects of different titanium contents on the lattice parameters,crystal structure,elastic constants and elastic modulus,The effect of varying the titanium content on the mechanical properties of the high-entropy alloy was predicted to provide a theoretical basis for the effect of varying the elemental content on the properties of the molten cladding.Finally,the high-entropy AlCoCrFeNiTi_x(x=0,0.2,0.4,0.6,0.8,1.0)series clad layers were prepared by laser cladding technology based on the optimum process parameters.The study also analyses the friction and wear mechanism and cladding reinforcement mechanism,as well as the comprehensive performance change mechanism of high entropy alloys in combination with the first nature principle.The results of the study provide a theoretical basis for the calculation of the coating performance control of high entropy alloys produced by laser melting based on the first nature principle of the generalised density theory,and provide technical support for the design and optimisation of the composition of laser-melted high entropy alloys.At the same time,it has a certain promotional value for laser additive manufacturing and repair of other high entropy alloy material parts.