Magnetorheological (MR) fluid jet polishing is a material removal process for precision products such as optical elements. It is characterized by a jet flow that is stabilized by a magnetic field, and a highly predictable machining spot. The behavior of the particles in an MR fluid slurry near a target wall surface is conceptually described. In experiments with a BK7 glass specimen, various removal spots are created by impingement of MR fluid jets at velocities of 10~30 m/s, using MR fluids of different compositions, and different processing durations. The tangential MR fluid flow along the part surface is assumed to be responsible for material removal, and theoretical models for the prediction of material removal are developed, using the conventional wear model and granular flow theory. The constitutive relation between the shear stress and the shear rate changes as the jet velocity increases, which has a critical effect on the behavior of material removal. CFD analysis is performed to calculate the wall shear rate. The proposed models agree with the experimental results with respect to the distribution of the material removal rate. Additionally, the surface topographies of polished parts are discussed, with regards to the particle behavior.
|Number of pages||9|
|Journal||International Journal of Precision Engineering and Manufacturing|
|Publication status||Published - 2015 Apr 1|
All Science Journal Classification (ASJC) codes
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Electrical and Electronic Engineering