CNC turning and milling composite processing. It uses the magnetic fluid formed under the action of a magnetic field to make the suspended non-magnetic abrasive particles press against the rotating workpiece under the action of the flow force and buoyancy of the magnetic fluid to grind and polish, thereby improving the finishing process. Quality and efficiency. It can obtain a machined surface with Ra≤0.01μm without a metamorphic layer, and can polish workpieces with complex surface shapes. Since the magnetic field lines of the magnetic field and the magnetic fluid formed by them do not directly participate in the removal of materials, it is called magnetic field assisted processing.

The magnetic fluid of CNC turning and milling composite processing is composed of magnetic particles, surfactants and liquid carriers (such as water, oil, etc.). The average particle size of the magnetic particles is about 10 urn. It is surrounded by the organic molecules of the stable surfactant and becomes a stable magnetic particle colloid, suspended in an oil-based or water-based liquid carrier.

For example, the CY3-1 type metallic magnetic fluid is made of Fe3O4 magnetic material with a particle diameter of 7.5-10nm (mass fraction 10%-30%), which is dispersed in mineral oil with the surfactant oleic acid (mass fraction 40%-60%) In the carrier, its saturated induction intensity is 0.023T, density is 1.2g/mL, and dynamic viscosity is 20×10-3Pa·s. CNC turning and milling compound processing, because the magnetic moment of the magnetic particles is extremely large, it will not be precipitated by gravity, and its magnetization curve has no hysteresis, the magnetization can increase with the increase of the magnetic field strength, so as to realize the force and the processing volume on the workpiece control.