Analysis And Research On Processing Surface Velocity And Stress Field Of Fluid Magnetic Abrasives

Fluid magnetic abrasives (FMA) are a new kind of precision finishing abrasives, which take advantage of the theory that the magnetism induces phase to change,in the absence of an applied magnetic field,FMA exhibit Newtonian-like behaviour ,can contact workpiece sufficiently. When exposed to a magnetic field ,the viscosity and yield shearing stress increases several orders of magnitude ,the FMA change from Newtonian fluid to solid,and this change is successive,reversible,in case of removing external magnetic field ,the FMA return to Newtonian fluid. The unique reheolgical property of the FMA makes it like a "soft" grinding wheel,can adapt to different profile of workpiece ,when there is relative movement between the FMA and workpiece,finishing is realized.The dissertation ,which is based on the existing study of the FMA,research into the FMA and its finishing systematicly with adopting combination of theoretical analysis and numerical simulation: first of all,the dissertation introduce concept,composition,physical properly,microcosmic rheological mechanism of the FMA,and also the correlative basic theory of FMA finishing mechanism,material removed model,experimental equipment,technical parameters,then sum up the existing microcosmic and macroscopical shearing stress model of the FMA, confirm flow state of the FMA during finishing with adopting critical Renault method,based on the confirmation of the flow state,establish hydrokinetics model of the FMA finishing with adopting the theory of non-newtonian liquid and tensor analysis and combining with biviscosity model,confirm kinematics and mechanics property of the FMA finishing,gained shearing stress and velocity field distributing of the FMA,then discuss and confirm analysis area of the FMA, analyse and compare with shearing stress and velocity field of the FMA, when in absence of and exposed to external magnetic field ,by virtue of finite element analysis software -ANSYS;finally,sum up the whole article,and present problem and deficiency during analysis,and bring forward next investigation work simultaneously.