Research On Multi-objective Optimization Of Process Parameters For Multi-channel Lap Laser Cladding

With the continuous development of automobile,shipbuilding,aerospace,construction machinery and other industries,more and more requirements have been put forward for manufacturing industry.As an advanced modern manufacturing technology,laser cladding technology has been widely used in alloy coating,surface damage repair,complex parts manufacturing and other fields.In the process of laser cladding,the overlap ratio,laser power,scanning rate and other process parameters play a decisive role in the surface quality and cladding efficiency of the cladding layer.At present,the research of laser cladding process parameters is mainly single-layer laser cladding.For the research of multi-channel lap laser cladding,the lap ratio is only selected on the basis of single-channel laser cladding,and the interaction between lap ratio and parameters is ignored.In the process of large area alloy coating preparation and surface damage repair,it is urgent to study the influence of lap ratio,laser power,scanning rate and other parameters on lap cladding quality.In order to improve the cladding surface quality and cladding efficiency,it is essential for us to study on the multi-objective optimization of laser cladding parameters.In this paper,the regression fitting model between multi-channel lap laser cladding process parameters and cladding quality will be established,and the multiobjective optimization of multi-channel lap laser cladding process parameters will be performed by multi-objective algorithm,and the optimized process parameters will be simulated and analyzed by finite element software.Firstly,the process parameters and quality parameters of multichannel lapped laser cladding are analyzed.Based on the data of multichannel lapped laser cladding test,a regression prediction model between process parameters and quality parameters of multichannel lapped laser cladding is established by using quadratic polynomial,RBF neural network and GRNN neural network,and the fitting errors of the above models are calculated.Comparing the calculated results,the model with the least error is chosen as the regression fit model for the multichannel lapped laser cladding.Secondly,a multi-objective optimization model for multi-channel lapped laser cladding is established based on the regression fit model of multi-channel lapped laser cladding.The multi-objective optimization and optimal solution search of the model parameters are carried out by the multi-objective particle swarm algorithm,and the solution results under different population sizes(20,30,40,50)and external storage capacity(50,150,250)are compared.The optimal set of solutions for the process parameters is obtained.Finally,the thermal-mechanical coupling finite element simulation model of laser cladding is established by using Abaqus software.The simulation results are compared with the experimental micro-images of the cladding layer to verify the accuracy of the finite element model.The orthogonal design of multi-channel lapped laser cladding simulation is carried out within the optimized process parameters combination range.The temperature and residual stress of multi-channel lapped laser cladding are simulated and studied under different process parameters combination.The significance of each process parameter on residual stress of laser cladding is obtained by variance analysis.