Study On Stress-strain Field And Microstructure Of The Local Laser Surface Treatment In Ni-base Alloy

This paper use ANSYS finite element analysis software to simulate processing of thelocal laser surface treatment in Ni-base alloy.Study on the sample’s temperature field,stress field and strain field and the rule of distribute. On this basis, we use the laser surfacetreatment test device which is developed by ourselves to do the local laser surfacetreatment in Inconel718and C-2000Ni-base alloy.We use the optical metallographicanalysis,scanning electron microscopy (SEM) analysis,X-ray diffraction analysis,hardnesstest and other modern analysis means.After the laser surface treatment,systematicallystudy on the stress and strain field, microstructure and properties of Ni-base alloy.Numerical simulation results show that the surface of C-2000Ni-base alloy have agreat temperature gradient after laser surface treatment. The temperature of irradiationcenter place is highest.We know the influence of laser irradiation limit temperature on thesize and the distribution of stress and strain field. By controlling the laser processingparameters, we can realize plastic deformation.The results of Ni-base alloy laser surface treatment experimental show that:Inconel718and C-2000Ni-base alloy of local laser surface treatment produce obviousplastic deformation. The degree of plastic deformation and hardness increases with theincreasing of laser irradiation temperature and cycling times. The depth of hardening layercan reach hundreds of micrometers.X-ray diffraction analysis and calculation show that crystal defect density increasesignificantly in the Ni-base alloy after crystallite size decrease and at the same time thelaser surface treatment cause residual stress and texture.