If you have read our previous article, it is easy to know:

The concept of magnetorheological fluid was first proposed by Rabinow J in 1948, which is a suspension composed of magnetic particles, base fluid, and stabilizers.

The magnetorheological effect refers to the phenomenon where a magnetorheological fluid is a flowable liquid without the application of a magnetic field, and its rheological properties undergo a sharp transformation under the action of a strong magnetic field, exhibiting properties similar to those of a solid. When the magnetic field is removed, its flow characteristics are restored.

Magnetorheological polishing technology utilizes the flexible "small grinding head" with viscoplastic behavior formed by the rheological behavior of the magnetorheological polishing fluid in a gradient magnetic field to have rapid relative motion with the workpiece. When the magnetorheological fluid flows through the workpiece and forms a small gap between the polishing wheel carrying the fluid, the shear deformation force between the workpiece and the magnetorheological fluid is used to remove the surface material of the workpiece.

Compared with traditional optical precision polishing methods, magnetorheological polishing has the following four main characteristics:

1. Able to obtain high-quality optical surfaces.

During the magnetorheological polishing process, due to the Controllability of the magnetorheological fluid, the yield stress in the solid state of the magnetorheological fluid can be adjusted, which is conducive to the generation of micro cutting effect, and the surface layer and sub surface layer of the workpiece will not produce compressive stress, so the surface layer of the workpiece will not be damaged, and it is easy to obtain high surface quality.

2. Easy to implement computer control, able to obtain relatively complex surface shapes.

By controlling the magnetic field, the size, shape and strength of the tool (the "convex ribbon" formed by the magnetorheological fluid in the magnetic field) can be controlled, so the processing of various surface shapes can be realized. Due to the Controllability of the magnetic field, it is easy to realize computer control and numerical control processing.

3. High removal efficiency.

Due to the addition of micro abrasives to the magnetorheological fluid, under the action of a controllable magnetic field, the magnetorheological fluid is equivalent to forming micro "grinding heads" to remove the material from the workpiece. At the same time, storing enough water in the magnetorheological fluid is conducive to the hydrolysis reaction.

4. There will be no tool wear or blockage.

During the processing, the abrasive debris of the material is carried away and filtered along with the circulation of the magnetorheological fluid. The medium in the magnetorheological fluid is water and organic salts, which do not scratch the machining surface of the workpiece and play a role in cleaning and cooling.

The numerical control magnetorheological polishing technology corrects the surface error of the workpiece by controlling the polishing trajectory, dwell time, and ribbon protrusion formed by the magnetorheological fluid in an external magnetic field through a computer. The combination of magnetorheological polishing and computer-controlled precision grinding has redefined the processing energy and competitive range of the precision optical industry, becoming a widely used optical component processing method.