Technology And Mechanism Of Surface Micro-groove Structure Fin In Extrusion-machining Process

With the functional characteristics of the surface micro-groove structure confirmed by scientific research,its potential application value and the use of the prospects caused widespread concern,it also contributed to the rapid development of micro-groove processing technology.At present,micro-groove processing technology is also difficult to meet the industrial low-cost,high-volume and high-quality manufacturing requirements.This paper presents a new method to prepare the surface micro-groove structure,which is a new forming process with coupling cutting technology and plastic forming technology: extrusion-machining.The technique is to copy the desired micro-groove structure onto the constraining tool,and then squeeze the machined flat plate into the micro-groove channel of the composite tool,which is combined with the cutting tool and the extruded block,forming a surface micro-groove stripe with a certain structure,size.In this paper,the finite element model of the surface micro-groove structure strip is established,and the extrusion-machining mechanism is analyzed.The extrusion-machining compound tool is designed and the preparation of the surface microgroove strip is carried out.And the influence of the key parameters such as the groove structure,the cutting extrusion ratio,the cutting rake angle,the corner radius of the extruded block,the friction coefficient between the cutting strip and the tool on the deformation parameters(equivalent stress,Temperature,forming force,etc.)and the forming effect were studied.Comparative analysis the finite element simulation results and experimental results to find out the optimization direction and application range of the extrusion-machining process.The main contents of this paper are as follows:(1)According to the change of forming force during processing,the forming process can be divided into four stages: initial cutting stage,extrusion forming stage,stable forming stage and forming end stage.With the cutting strip accumulated under the pressure in the composite tool micro-groove channel,forming force to reach the maximum value,meanwhile,the forming effect has reached the limit.The results show that the forming height of the exit end of the surface micro-groove strip is smaller than the forming height of the inlet end.(2)In the stable forming stage of extrusion-machining,the equivalent stress and temperature of the bottom and side walls of the forming groove,the forming height of the micro-groove and the forming conversion rate are analyzed under different key parameters.The results show that the inner wall inclination angle of the groove structure,the bottom space of the groove,the cutting extrusion ratio,the cutting rake angle,the radius of the extruded block corner angle and the friction coefficient between the cutting strip and the tool all have obvious influence on equivalent stress,temperature and micro-groove structure forming effect.(3)Comparing with the experimental results and finite element simulation of the forming processing,and the finite element simulation parameters are verified.The theoretical model of high reliability and guidance fins can be guided.As long as using the appropriate extrusionmachining process parameters,it will be able to get better shape of the surface micro-groove structure fins,and which is conducive to improving its direct application in the industrial field value.