Research On Deformation Control Method Of Laser Cladding For Thin-walled Parts

Laser cladding technology,as one of the pillar technologies of green remanufacturing,has the advantages of saving energy,obtaining good metallurgical bonding coating,and is widely used in repairing damaged parts.Thin-walled parts widely exist in energy,petroleum,aerospace and other fields,which have high manufacturing cost and high remanufacturing value.In laser cladding repair of thin-walled parts,attention should be paid not only to the forming quality of cladding layer,but also to the deformation of parts.Therefore,the laser cladding repair of thin-walled parts is more complex than the repair of other large parts.This paper mainly focuses on reducing the deformation of thin-walled parts and improving the forming quality.The main research contents and conclusions are as follows:(1)The sequential decision-making method of laser cladding scanning for thin-walled parts was studied.The transient solution of temperature field of thin-walled parts was solved by ANSYS software.Taking the temperature difference between the upper surface of the cladding layer and the lower surface of the substrate as the solution criterion,the scanning sequence planning for laser cladding of thin plates was carried out.This method was called the minimum temperature range method in this paper..By comparing the temperature field between the minimum temperature range method and the traditional scanning method,it was found that the maximum temperature of each channel of the traditional scanning method was generally higher than that of the minimum temperature range method.(2)In order to verify the correctness of the established temperature field model of thin plate and verify that the minimum temperature range method could improve the forming quality and control the deformation of thin-walled parts,a thermocouple temperature acquisition system was built,and the correctness of the temperature field model was verified by comparing the experimental acquisition temperature with the simulated temperature;the deformation results of cladding by the one-way sequential scanning method and the minimum temperature range method were compared with the forming process.By comparing and analyzing the quality,it was proved that the minimumtemperature range method could reduce the deformation of thin-walled parts and improved the forming quality.(3)On the basis of the previous single-factor and single-pass experiments,the influence of laser cladding process parameters on the deformation behavior of thin plate was studied by orthogonal experiment.The optimal process parameters for controlling the deformation of thin plate were found as follows: laser power 600 W,scanning speed 12 mm/s,powder feeding rate 1.2 r/min;microhardness and SEM analysis of thin plate with minimum deformation were carried out,and the results showed that the microhardness was obvious.The cladding layer has good metallurgical bonding with the base metal.(4)In order to verify that the minimum temperature range method could reduce the deformation of laser cladding thin-walled parts,two scanning methods were used to clad thin-walled parts under the optimum technological parameters.By comparing the cladding results,it was verified that the minimum temperature range method could significantly reduce the deformation of thin-walled parts cladding,and Compared with the one-way sequential scanning method,the minimum temperature range method reduced the deformation by 47%.