Study Of Morphology Optimization And Tribological Properties On The Drawing Mold Surface By Laser Texturing

According that the function of mold is one of the key factors to materials forming,there is an urgent need in studying the new method to improve the quality of sheet metal forming.In this paper,in order to achieve the optimization of laser texturing morphology geometric parameters,based on the fully understanding of application of laser texturing at home and abroad,the numerical optimization combined with the experiments construct the main body of the article,the optimization method is used on the morphology numerical optimization of friction coefficient,and the friction result of laser texturing morphology is used to verify the numerical optimization.The main research contents and result are in the following areas:First of all,according to the drawing numerical simulation of curved parts basket, it is found that the frictional resistance of flowing at the sheet metal flange has an important impact on forming properties,then,the friction model in different regions of the mold surface and the mechanism of laser texturing technology on the die surface are analysised during the drawing process of sheet metal,and the based theoretical for optimizing the distribution of laser texturing morphology is provided.Secondly,according to the tribological model in drawing process,the mathematical model of frictional coefficient is set up considering the adhesive friction,boundary membrane elements shear stress,pears and lubricants groove shear stress from the asperity contact with each other.The mathematical model shows the relationship between the frictional coefficient and geometric parameters(asperity number n,asperity radius r and the diameter of the interface asperity w).This mathematical model is used as a minimum objective function with the optimization method,the distribution of asperity is equidistant,m,r,w are as variables,the expertise function is selected as constraint conditions,and the hybrid iterative penalty function method is used to settle the optimize problem contained multi-variable. Taking into account the integer optimization,and in view of the theoretical difficulty of mixed integer optimization algorithm,the values of n is exhaustive in this paper, corresponding to the various n,the mathematical model is optimized solved with the variables m,r and w.Finally,the experiment of laser-texture to surface is studied,five samples is selected for the study,based on the result above,the corresponding morphology of required parameters is processed.The tribological experiments are taken to the samples,and the result of these experiments are compared with the results of numerical optimization,and there are in good agreement,it shows the validity of the results and numerical optimization can be used to the optimization of laser-texturing morphology in drawing mold surface.The results show that:In the case of a certain process conditions,the surface friction coefficient has a great effect on the loading of parts,if the conditions of the permit, changing the surface morphology is easy to get a better forming quality.Different laser texturing morphology has different tribological properties is proved by the numerical optimization,and the reliable texturing morphology parameters can be obtained by numerical optimization.The texturing process can be taken according to the obtained parameters,and get the best friction coefficient distribution on drawing surface.