Key Technology Of Magnetic Field Assisted Micro Abrasive Water Jet Polishing Ceramic Materials

Micro abrasive water jet machining technology has important research value because of its characteristics,such as no tool wear,small reaction force,high flexibility and no thermal deformation.In this paper,the magnetic field is applied to the process of micro abrasive water jet machining,which reduces the divergence of jet,enhances the collimation of the jet,raise the abrasive speed and improve polishing efficiency.The specific research contents are as follows:A micro abrasive water jet auxiliary magnetic field generator is developed.Using theoretical calculations,numerical simulations and experimental verification methods,a magnetic field generating device suitable for micro abrasive water jet machining was developed.By designing the main parameters of the magnetic field coil,the distribution of the magnetic induction intensity produced by numerical simulation is simulated and the test is carried out.The results show that the uniform magnetic field is generated near the nozzle axis,which provides a positive external environment for accelerating and orderly arrangement of magnetic abrasives in nozzles.A magnetic field assisted abrasive water jet flow field distribution law is developed based on COMSOL software.Using the flow field module,the particle tracking module and the AC/DC module in the software,the distribution of the jet flow field under the magnetic field is simulated and the trajectory of the magnetic abrasive in the jet flow field is simulated.The results show that after the application of the auxiliary magnetic field,the diffusion of the jet is obviously weakened,the effect of the cluster is improved,and the velocity of the abrasive in the jet is increased by about 10%.By analyzing the influence of jet pressure,abrasive flux and the excitation current on the distribution of the jet flow field,the results show that the jet pressure and excitation current have a great influence on the flow field distribution of the jet.Magnetic field assisted micro abrasive water jet polishing ceramic materials are experimentally studied.The single factor and orthogonal test method was used to study the process technology of magnetic assisted micro abrasive water jet polishing ceramic materials.The experimental results show that the material removal after the application of a magnetic field is increased and the surface quality is improved.The influence of processing parameters on the surface roughness of alumina ceramics is also analyzed.The results show that the jet pressure,excitation current and magnetic abrasive particle size have a greater influence on the roughness after polishing,and the surface roughness of ceramics decreases first with the increase of jet pressure,the larger the magnetizing current is,the smaller the surface roughness of the ceramic is,and the finer the magnetic abrasive is,the smaller the surface roughness is.