Reserch On The Geometrical Model Of Cross-section Morphology Of Single Laser Cladding By Powder Injection

As a new advanced manufacturing technology, laser cladding has extensivedevelopment and application in recent years. In practical production, cladding layer on thesurface of the workpiece is composed of overlapped single laser claddings. The surfacequality of the whole cladding layer is greatly influenced by the cross-section geometricalmorphology of each single cladding layer. Therefore, to exactly control the geometricalmorphology of cladding layer and improve the quality of the cladding layer, it is essentialto study the geometric model of the single cladding layer cross-section morphology andestablish the functional relationship between the processing parameters and the geometriccharacteristic parameters of single cladding layer cross-section.The present paper adopts the steel Q235as the matrix and stainless aerosol powder316L as cladding material. The single laser cladding experiment is carried out with thecontrollable processing parameters as variables, including laser power, scanning speed andpowder feeding rate. The height, width and the area of cladding layer and the contactangle are measured respectively in the present paper.Through the observation of cross-section morphology of single cladding layer underdifferent processing parameters, two entirely different cross-sectional morphologies can befound. A new model describing cross-section geometrical morphology and controlled byparameter δ is proposed. The experimental data is disposed by applying linear regressionmethod, though which the functional relationship between parameter δ and nominal areaFmcan be obtained. The model is verified by comparing the measured area of claddinglayer cross-section and contact angle with the calculated value.According to the experimental results, the influence of laser power, scanning speedand powder feeding rate on the macro profile of single cladding layer cross-section isanalyzed, based on which the experimental results are analyzed by applying linearregression method and the functional relationship between the width, height andmorphology characteristic parameters of single laser cladding layer and processingparameters, is established.According to the functional relationship between width, height and morphology characteristic parameters of cladding layer and processing parameters, the geometricalcharacteristic of single cladding layer cross-sectional morphology is predicted on theplatform of MATLAB. Single laser cladding experiment is carried out under differentgroups of processing parameters collected within the predictive range. Through thecomparison of the predictive results and the experimental results, the accuracy of themodel established in the present paper is verified.