How does MRF work?
At the heart of every MRF polishing system is the MRF delivery system which creates stable, continuous, flow of MR fluid. The MR fluid is a magnetically-sensitive (magnetorheological) “smart fluid” which changes viscosity in milliseconds when exposed to a magnetic field. The magnetic field creates stiff structure of iron particles which forces water and abrasives to top in a thin layer. A converging gap is created. Cores are formed, creating sheared layer of fluid. Pressure gradients result and high-velocity, shear-based removal is created.
A workpiece is installed at a fixed distance from a moving spherical wheel. An electromagnet located below the wheel surface generates a magnetic field in the gap between the wheel and workpiece. When the MR fluid is delivered to the wheel, it is pulled against the wheel surface by the magnetic field and the act of plunging the workpiece into the ribbon of MR fluid creates a subaperture polishing tool. A sophisticated computer program determines a schedule for varying the position of the workpiece as it sweeps through the polishing zone, in either a spiral or raster path.
A computer numerical controlled, precision workstation and sophisticated computer algorithms help ensure that the MRF Polishing System is automated and robust. An easy-to-use touchscreen interface guides the operator through every step of the automated process. Stability, predictability and repeatability characterize every MRF polishing cycle.
MRF polishing equipment is intuitive and easy-to-use:
- Optical surface errors are fully characterized on an interferometer and transferred to the MRF system
- User-friendly software calculates the optimal toolpath required to correct the surface errors
- Pre-run setup is verified with an integrated simulation
- Real-time progress bars monitor status during polishing
- Advanced analysis features evaluate final results