Magnetorheological polishing method and device for the inner wall of titanium alloy tube. Under the action of peristaltic pump, magnetorheological fluid is pumped into the inner cavity of the polishing head along the inner surface of the transmission rod, overflow through the rectangular holes around the middle of the polishing head, and flow to the polishing area from the left and right sides respectively. Under the action of magnetic field, the apparent viscosity and shear yield stress of magnetorheological fluid increase rapidly, forming a Bingham medium with certain viscoplasticity. With the relative movement of the polishing head and the tube wall, Bingham medium cut and removed the tube wall material. After the polishing, the Mr Liquid is collected by the Mr Liquid collecting mechanism on both sides of the pipe, and after filtering and stirring, it continues to participate in the polishing process to realize the recycling of Mr Liquid. The heat generated in the polishing area is taken away during the magnetorheological fluid circulation. The invention can automatically polish the inner wall of a titanium alloy tube, has the advantages of simple control, good polishing uniformity and high working efficiency, and is especially suitable for polishing the inner surface of a slender titanium alloy tube.
Titanium alloy is a typical difficult-to-process material with low elastic modulus, large elastic deformation and high chemical activity. The surface surface of the workpiece is prone to changes in surface morphology, surface structure, composition distribution and hardness distribution caused by the combined effect of grinding force and grinding temperature. In severe cases, thermal damage such as burns and cracks will occur. In the prior art, electrochemical polishing is the use of electrochemical reaction to remove the residual micro-unflatness of the cutting process, which is not affected by the material and surface hardness of the workpiece, but there are many factors affecting the polishing effect, and the processing shows certain instability. The magnetic grinding process uses the magnetic grinding brush formed by magnetic abrasive under the action of magnetic field to polish the workpiece surface, which is widely used in the finishing processing of flat surface, inner and outer circular surface and complex mold cavity, but there are defects such as low grinding efficiency, high grinding cost and low life.
Magnetorheological polishing is a kind of precision machining technology, which is based on the rheological effect of magnetorheological fluid to polish the workpiece surface. Under the action of gradient magnetic field, the apparent viscosity of magnetorheological fluid increases rapidly, forming a viscoplastic Bingham medium with a certain shear yield stress. The workpiece surface is polished by its rapid relative movement with the machined surface. Magnetorheological polishing is not limited by the surface shape of the workpiece, has little pressure on the surface of the workpiece, does not cause sub-surface damage, and has stable material removal and high controllability.
