Mechanism And Experimental Study On Magnetic Compound Fluid Surface Grinding For Ductile Material

With the development of science and technology,all professions and trades make a higher demand for surface accuracy and surface quality.The high-precision aspheric parts are especially used more and more widely.The surface finishing technology of aspheric parts is always the difficult issue.Because traditional processing methods exist grinding head aging,mismatch of workpiece-lap,instability of removal function and other shortcomings,which result in the process uncontrolled,lower processing efficiency.It is difficult to obtain high-precision surface.Besides,the automation of finishing is hard to come true because of instability of the removal function.As a new-style and high deterministic finishing technology,magnetic compound fluid(MCF)grinding can overcome the shortcomings of traditional processing method.In manufacture process,the efficient and stability of removal function must be ensured and the law between removal function and surface feature must be grasped to realize the efficient and automation of magnetic compound fluid grinding technology.Therefore,this paper carried deeply study on these two aspects and conduct experiments to validate the mathematical model.The main contents of this article: 1.Design the grinding head for curved surfaceDesign the grinding head for curved surface,which has more advantages than old one.Carried out the finite element magnetic field simulation and tested the distribution of magnetic field strength of the magnetic pole.The simulation result and the test result are consistent with theoretical analysis.Conduct comparative experiment of magnetic poles,came to some conclusions.First,When the curvature of magnetic pole is similar to the workpiece,the effect of grinding is the best.Second,the effect of grinding using slotted magnetic poles is better than magnetic pole without slot.Third,the effect of grinding using the magnetic pole with two slots is best.2.Establish mathematical models of magnetic compound fluid grindingEstablishing mathematical models of magnetic compound fluid grinding contributes to the realization of automatic control.By using the theory of micro cutting,solved the material removal shape of magnetic compound fluid grinding.By using the Preston equation,established the mathematical models of material removal efficiency.Simplifying material removal mechanism of magnetic compound fluid grinding,established mathematical model of surface roughness.3.Conduct material removal experimentsConducted experiments for my research contents to verify the rationalities of the mathematic model established and solve the parameters in the mathematical model.The error between the experimental results and the simulation is 10%.Through calculating the parameters,came to two conclusions.One is that Preston coefficient is reduced with the increase of the inclination angle on the surface of the workpiece.This shows that the other factors is not conducive to grinding with the increase of the inclination angle in addition to the magnetic field strength and the speed of abrasive materials.The other one is that for the same workpiece surface,the parameter a in the roughness mathematical model is a fixed value.Based on copper material,conducted experiments considering the effect of curvature and slope on surface grinding.And verified the correctness of the material removal model and surface roughness model,determined the related parameters.