Study On The Influence Of Fluid Magnetic Abrasive Hole Finishing Parameters On Processing Effect

As an important mechanical characteristic, holes widely exist in aerospace,ships, weapons, medical equipment and other related products.Its inner surface quality has an important influence on the transmission of fluid and the friction between the moving pairs.The results can further affect the stability, reliability and service life of the whole mechanism.However, most of hole finishing technologies have limitations and is difficult to solve the finishing problems on micro holes,step holes, cross holes and other special shaped holes.For this purpose, our research group put forward a new technique of finishing hole.The technology has the advantages of high quality, strong shape adaptability,controllable grinding force and so on.It has a special advantage on finishing small holes and other complex cavity and high research value.In view of the situation lacking the basis when Selecting processing parameters, this paper mainly studies the following contents:1)Study on the mechanism of hole finishing by Fluid Magnetic Abrasive.The rheological properties of Fluid Magnetic Abrasive is analyzedapplying magnetic domain theory, phase nucleation theory and dipole moment theory.The dipole moment theory has more advantages in practical calculation and interpretation of strength.The micro material removal mechanism of finishing is analyzed and find that the material removal form is mainly micro cutting and fatigue removal.The shear force model of single abrasive and the "double edge circle" model are compared and the influence of abrasive particle size on the machining effect is obtained.A material removal rate model based on the classical Preston formula was established. The main parameters which influence the material removal rate is obtained,also the influence law.2)Hole finishing by Fluid Magnetic Abrasive.In order to verify and supplement the conclusions obtained from the processing mechanism researching,hole finishing experiment was carried out.According to the processing mechanism, the whole design of the experimental device for finishing hole is carried out.The double closed loop for Fluid Magnetic Abrasive is designed.The selection and design of magnetic field generating device and extrusion device are carried out.Design and manufacture the fixture.The effects of processing time, abrasive particle size, current intensity and inlet pressure on the finishing process were studied.3)Analyze the influence of processing parameters on the surface roughness.The measuring index of the processing effect is the reduction of the roughness.Orthogonal experiment was designed.Through the analysis of variance,the influence of main process parameters on the roughness reductionrate was obtained.The rationality of the results of variance analysis was verified by the Grey correlation analysis method.The influence degree processing time on roughness reduction rate is the highest and Followed by abrasive diameter,inlet pressure, current intensity.4)A prediction model for roughness reduction rate on process parameters is established.In order to obtain the exact relationship between the main process parameters and the roughness reduction rate,a multi-variable Grey model is established on the basis of grey prediction theory and multiple linear regression model.The model reduces the fluctuation error of the independent variable and improve the prediction accuracy.Finally,it is proved combined with the experimental data that the model has high prediction accuracy and strong anti-interference ability.This paper studied the influence of process parameters on processing effect by theoretical analyzing and experiment studying. The research results provided a theory basis and methods when selecting the processing parameters in the process of finishing hole by Fluid Magnetic Abrasive.