The Technology Research Of Magnetic Abrasive Preparation Method By Free Fall Gas Solid Dual-Phase Flow Atomization And Magnetic Abrasive Finishing

Magnetic abrasive as the tool of magnetic abrasive finish(MAF),its performance and quality directly affect the quality and effectiveness of magnetic abrasive finish.Hence,the technology for preparing magnetic abrasive has become the key to promote the application of MAF.Our research group proposed a way that called ’preparation of magnetic abrasives by gas atomization with rapid solidification’ in 2007 and the method was proved to be a promising behavioral approach for preparing high performance magnetic abrasive.But this method still has many problems that need to be got inside the experimental equipment,the preparation process and deep preparation mechanism.Therefore,our group makes a new method that called ’magnetic abrasive preparation method by free fall gas solid dual-phase flow atomization’.Based on studying the technology for preparing magnetic abrasive in depth,a new dedicated device is designed for preparing magnetic abrasive by depending on improving the traditional system of preparation powder.And the equipment for conveying hard abrasive and atomizer are studied.With regard to the equipment for conveying hard abrasive,it is designed to achieve the delivery function and in further to achieve the quantitative delivery function.Based on a deep understanding of MAF,a miniature magnetic abrasive finishing machining center is designed and the CNC system including hardware and software gets an initial design simultaneously.The atomizer,in the atomization system,is an essential part.It plays a key role in the process of atomization and can make the stability and efficiency of atomization.This paper provides analytic depth about atomization medium flow and structural parameters of atomizing nozzle in theory and a new plan is proposed to design a gas solid dual-phase flow double-layer atomizer.Meanwhile,structural and process parameters are discussed on the flow field of the atomizer by using FLUENT software numerical simulation.By comparing the characteristics of the flow field under different structural parameters,we can get the optimal structure and process parameters of the gas solid dual-phase flow double-layer atomizer,among which the atomizer taper angle is 40 degree,crack width is 0.4mm.The pitch diameter of the second sprayer for 40 mm,taper angle is 90 degree,crack width is 0.8mm.By comparing the characteristics of the flow field with the same structural parameters at different pressures has been simulated.It is discovered that the effect of the flow field is stable when the lower gas pressure is 20 atm and the upper gas pressure is 4atm.The three-dimensional solid model of the micro magnetic abrasive finishing machining center is established with SLIDWORKS.The CNC system is developed by a double CPU structure of IPC+PMAC.Based on this kind of advantage,the hardware structure of the system is simpler and has a better real-time,stability and extensibility.In addition,the CNC system software is designed on the Windows XP operating system,so it can make extensive use of computer resources,shorten development times and be easy to realize the software module.The machine can offer an important condition for finishing the micro surface automatically,which has a high practical value.