Estimation of magnetorheological fluid constituent’s concentration for efficient finishing process

ABSTRACT

Efficacy and outcome of all magnetorheological finishing (MRF) processes depend on rheological properties of the magnetorheological (MR) fluid which consists of carbonyl iron particles (CIPs), abrasives and carrier fluid. Thus it is important to understand particle distribution in MR fluid which affects the rheological properties of the fluid under the influence of the applied magnetic field and hence the finishing process. A hexagonal microstructure model of MR fluid is considered and a modified model of abrasive doped MR fluid is developed for generation of estimation curve based on ratio of size of abrasive particles to CIP. MR fluid was prepared based on these estimated values and was used for finishing of N-BK7 glass on Ball End MRF (BEMRF) machine. MR fluid with four different abrasive size to CIP size ratios were prepared with CIP volume fraction of 32.9% and Cerium Oxide particles volume fraction of 12.5% with 54.6% water. Another experiment with size of cerium oxide particles to size of CIP ratio of 0.761 is taken for four different concentrations of abrasives and CIPs. Best results with 79.85% improvement in roughness and 0.672 µg/minute MRR were obtained for fluid prepared as per proposed estimation curve for efficient finishing process.

KEYWORDS:

• Efficiency
• finishing
• modeling
• magnetic
• microstructure
• particles
• rheology
• roughness
• MRR

Acknowledgments

Authors acknowledge interesting and insightful scientific inputs and discussions with Dr Gufran S. Khan, Associate Professor, IIT Delhi. Authors also acknowledge Mr. Vinod Mishra, Senior Technical Officer for help in measurements.

Additional information

Funding

This work was supported by the DST, Government of India, New Delhi [DST/TSG/FF/2011/188].