Study On Surface Topography Characterization And Friction And Wear Performance Of Ball-end Milling

The surface topography characteristics of the workpiece are closely related to its functional characteristics,and reasonable topography characteristics can make the surface have more excellent friction and wear characteristics.Therefor,there must be a close relationship between surface topography with friction and wear characteristics,but the relationship between the two was still unclear.The surface roughness parameter is the most intuitive and effective reflection of the surface topography and can realize the quantitative characterization of the surface quality.For this reason,this article takes the ball-end milling surface with the scallop-shaped pit structure as the research object.According to the special edge line structure of the ball-end milling cutter and the contact method of the cutter,by changing the processing parameters,the initial phase difference between the tool and the workpiece,the tool vibration and other related factors,the machined surface with different topography characteristics can be obtained.Aiming at the actual problem that the relationship between surface topography and functional characteristics was not clear under the influence of multiple factors in the ball-end milling process,the method of finite element simulation analysis is used,combined with the proposed gray change correlation model,and the correlation between three-dimensional surface texture parameters and contact area,wear depth change rate and friction coefficient was obtained,and a friction and wear characteristics prediction model based on three-dimensional surface texture parameters was established.The specific research contents include:First of all,based on the idea of grey system theory,a grey change correlation model is proposed for the basic characteristics of different dimensions and varying amplitude between the three-dimensional surface texture parameters and the friction and the wear characteristic parameters.Through the overall perspective of parameter interval change rate,the correlation analysis model between different dimension parameters is established.On this basis,the prediction model of system characteristics under multiple parameters is improved.The research results provide theoretical support for the follow-up research of the thesis.Secondly,establish the three-dimensional topography model of the ball-end milling surface under the influence of three factors: processing parameters,the initial phase difference between the tool and the workpiece,and the tool vibration.Extract the surface topography point cloud data of different models,and completes the calculation of the three-dimensional surface texture parameters of different models based on the ISO25178-2 standard.Combining the changing laws of surface topography characteristics under different influencing factors,effectively distinguish the influence of different factors on surface topography.It provides a new way of thinking for the study of surface friction and wear characteristics under the influence of different factors.Third,use ABAQUS finite element analysis software to establish a finite element simulation continuous dynamic analysis model of the sliding wear process.Based on the Archard wear theory,the Umeshmotion subroutine is written in Fortran language,and combined with ALE adaptive mesh technology to realize the automatic repartition of the model mesh during the sliding process.Dynamic extraction of the contact area,contact pressure,wear volume and other parameters in the sliding wear process has established a new method for the study of surface friction and wear characteristics under different topography characteristics.Then,according to the friction and wear characteristics of different surface topography in the sliding process,the rate of wear depth change for evaluating the surface wear characteristics in the stable phase is proposed.Combining the theory of gray change correlation degree,the correlation sequence of three-dimensional surface texture parameters is obtained of contact area and wear depth change rate,the evaluation parameters of friction and wear characteristics are extracted,and the influence of surface topography characteristics on the sliding wear process is analyzed.The research results can solve the difficult problem of the analysis of the influence of different influencing factors on the surface friction and wear characteristics,and reveal the influence mechanism of the surface topography characteristics on the functional characteristics.Finally,the experimental processing surface of ball-end milling under the combined action of the processing parameters,the initial phase difference between the tool and the workpiece,and the tool vibration is the research object,and the correlation characteristics between the three-dimensional surface texture parameters are analyzed.Establish the characterization system of the ball-end milling surface topography,complete the correlation analysis and prediction evaluation between the three-dimensional surface texture parameters and the friction and wear characteristics.The research results effectively solve the problem of surface topography evaluation and characterization of ball-end milling and prediction and evaluation of friction and wear characteristics.