Multi-Objective Optimization Method For Remanufacturing Laser Cladding Process Parameters

Laser cladding technology,as an important repair means of high-end mechanical equipment remanufacturing,has been widely used in aerospace,mining machinery,weapons and other fields.However,in the process of laser cladding,the quality of the cladding coating is determined by the process parameters and their interactions,and the shape control of the cladding coating can be achieved by optimizing the process parameters.Therefore,in this paper,funded by the National Nature Foundation project "Service life Prediction Method and Experimental Research of Additive Remanufacturing mechanical Parts(51505268)",multiobjective optimization research on laser cladding process parameters is carried out.The main research contents are as follows:Firstly,the parameters of single-pass laser cladding process were optimized.The laser power,scanning speed and powder feeding speed were selected as the input values,and the cladding layer’s aspect ratio,dilution rate and microhardness were selected as the response values.Based on orthogonal table,16 groups of experiments are designed,and the optimal results are obtained by range analysis.SPSS was used to discuss the experimental results and analyze the influence and trend of each parameter on the final response value.Secondly,based on the optimal combination of laser single-pass cladding process parameters,the multi-objective optimization of multi-pass cladding process parameters is studied.The laser power,scanning speed and powder feeding speed were selected as the input values,and the integrity,dilution rate and microhardness of the cladding layer were selected as the response values.20 groups of central composite experiments with 3 factors and 5 levels were designed using the response surface method.Based on principal component analysis,the comprehensive target value is obtained after normalization.The adaptive multiple linear regression function required by the intelligent algorithm was fitted as the fitness function by Design-expert software,and the residual plot,perturbation plot,response surface plot and contour plot corresponding to each parameter of the comprehensive target model were established.Then the adaptive differential chaotic evolution algorithm was used for multiobjective optimization,and experimental verification was carried out on this basis.Finally,taking the cylinder outer wall of fully mechanized mining hydraulic support as an example,the cylinder is pretreated according to the technological requirements,and the waste cylinder outer wall is repaired by using the best technological parameters obtained.After laser cladding remanufacturing,the cylinder was sampled,and the mechanical properties(tensile properties,shear properties,impact properties),wear resistance and metallographic structure of the specimen were analyzed.Determine whether the repaired cylinder performance meets the expected purpose.