Research On Electrical Conductivity Detection Of Melt Cladding Based On Electrical Resistance Tomography

Laser cladding layer inspection is a prerequisite for achieving laser cladding layer structure study.Aiming at the special complexity of laser cladding layer structure,it is usually difficult to obtain the structure information directly.In this paper,we propose a laser cladding layer conductivity detection method based on resistive laminar imaging with the goal of laser cladding layer conductivity detection,and design a high-precision cladding layer conductivity hardware detection system by optimizing the hardware system and image reconstruction algorithm,and the main work is as follows.(1)Construction of a laser cladding conductivity detection method based on resistive chromatography imaging.The basic idea of laser clad layer conductivity detection is determined by analyzing the process of tissue structure change of laser clad layer,combining it with the mechanism of clad layer conductivity,and constructing the method of clad layer conductivity detection based on resistive chromatography imaging to lay the foundation for the subsequent research.(2)Design of laser cladding layer conductivity detection system.Based on the theoretical knowledge of resistive tomography hardware system to optimize the design of the laser cladding layer conductivity detection hardware system,the positive and inverse problems in the theory of image reconstruction system are elaborated for the subsequent positive and inverse performance.(3)Numerical simulation of laser cladding orthorectified model.The mathematical model of the electrical orthodynamics of the melt layer and the finite element model of the electrical orthodynamics of the melt layer are established,and the modeling of the laser melt layer null field and mixed field models and modeling calculations are carried out based on the finite element method for the laser melt layer orthodynamics problem,and the different model parameters conditions(boundary conditions,profiling accuracy)are compared and analyzed to provide models and initial conditions for the subsequent inversion.(4)Optimization of laser cladding layer inversion algorithm.On the basis of the melt layer electrical orthorectification model,the image reconstruction algorithm for melt layer conductivity detection is explored and studied,and the reconstructed images of LBP algorithm,conjugate gradient algorithm and Newton-Raphson algorithm are simulated and analyzed,and the image reconstruction results are objectively analyzed and evaluated based on the image quality evaluation index,so as to provide an image reconstruction algorithm for laser melt layer conductivity detection.(5)Laser cladding layer conductivity detection experiments.In order to further verify the effectiveness of the electrical conductivity detection method based on resistive tomography,a laser cladding experimental platform and a laser cladding hardware experimental platform were built,different types of laser cladding specimens were fabricated,the optimized laser cladding detection system was used to measure the boundary voltage values of the cladding layer,and the super-resolution Newton-Raphson image reconstruction method was used to reconstruct the electrical conductivity image of the cladding layer.The results show that the laser cladding hardware inspection system built in this paper can accurately reproduce the location and contour shape of the heterogeneous bodies on the surface of the cladding layer and realize the cladding layer conductivity detection.