Research On Visual Inspection And Recognition Method Of Molten Pool For Laser Cladding Process

Laser cladding is a new special processing technology,which is irradiated by high energy laser beam to the surface of the material to be processed,quickly fused,expanded and rapidly solidified.The key is morphology detection of laser cladding pool.The relationship between the quality of the coating and the process parameters(powder feeding speed,laser power and scanning speed)is explored by detecting the shape of the weld pool,revealing the influence of key process parameters on the cladding layer,cladding process provides optimized operating parameters database.Firstly,the characteristics of the laser cladding arc distribution and the brightness distribution of the image in the bath area are analyzed.The advantages and disadvantages of various sensors are compared.The CMOS image acquisition sensor is used as the sensor type for the weld pool detection.Noises such as arc and splash interfere with the installation of 5mm thick quartz glass on the front of the camera to protect the lens and camera from molten pool splash particles.At the same time,neutral attenuators with a light transmission of 10%and 632.8 are selected.The nm filter attenuates the amount of incoming light and enhances the sharpness of the inside of the bath in the image,and creates a camera-specific bracket that facilitates the relative position of the camera and the puddle while maintaining stability.Secondly,the collected weld pool image is filtered,denoised and binarized,and a relatively clear image of the weld pool is obtained.Binarization in morphology is used to remove the interference caused by cathode atomization in the welding process.The weld pool defect detection and RANSAC ellipse fitting is used in this paper in the pretreatment of weld line image,and distinct weld line image can be obtained.All of these build up a strong background for the weld line information detection.Through edge characteristic information identify arithmetic,the exact weld pool width,length and area are obtained information can be obtained,which provided strong support for studying the influence of key process parameters on the cladding layer.Then,combining the most widely used in enterprise production,the laser cladding experiment with QT450-10 cast iron as the base material and Ni30AA powder as the cladding material is designed.The preliminary study on the cladding layer and the weld pool imaging law under different laser process parameters(laser power,scanning speed and feed rate)is done.