Optimization of process parameters in nano-finishing of Co-Cr-Mo alloy knee joint

ABSTRACT

Process of obtaining a high surface finish value, say Ra value, with the lowest standard deviation on the freeform surfaces especially on knee joint using the conventional finishing processes is an exigent task. Achieving a throughout uniform surface finish using a process called Rotational Magneto-rheological Abrasive Flow Finishing (R-MRAFF) is found to be a suitable approach with a designed, developed, and fabricated tool as an inverse replica. An inverse replica of femoral as a tool used for finishing where the medium flow is almost constant (minimum possible variation in velocities). To optimize the parameters, an effort has been made for reducing the time and achieving the more consistent surface finish. Total finishing time is reduced from 64.7 h to 2.0 h with a very low standard deviation of the final Ra value range over the surface of femoral. The minimum roughness of 50 nm is obtained which was originally 190.5 nm.

KEYWORDS:

• Inverse replica
• freeform surface
• knee Joint (Femoral)
• nano-finishing
• R-MRAFF
• MR fluid
• abrasion
• statistical technique