Die-Sink Electric Discharge Machining (DS-EDM) is a preferred advanced method, used to produce the complex geometry, cavities, die, and mold facing difficult in cutting the materials. In the current research work, machining of AISI420 stainless steel with copper electrode has been performed. Gap voltage (V), Pulse current (A), and Pulse on time (T) are considered as machine control variables (MCV) and material removal rate (MRR) and electrode wear rate (EWR) as measured machining performance. Experiments have been designed with the assistance of the Taguchi technique and further, Taguchi-Grey Relational Analysis (T-GRA) is executed to optimize the MCV. Parametric analysis is carried out to observe the implications of MCV on the measured machining performance. After interpretation the observations, it has been analyzed that the factors A, V, and T influenced 63.71%, 13.26%, and 10.88%, respectively, on the optimal explication. The fittest method positions have been confirmed by conducting a validation test. It has been explicitly proved that multiple performance characteristics in the DS-EDM method have been considerably enhanced by the T-GRA technique. The rise in grey relational grade is 0.086 by using the T-GRA technique.

Magnetorheological fluid-based finishing (MRFF) process is widely used for fabrication of optical material such as glasses, lenses, mirrors, etc. Performance of the process is significantly affected by the properties (size, concentration, hardness, etc.) of the constituents of MR fluid. MR fluids have been prepared by varying three abrasive particles mean sizes (4 µm, 6 µm and 9 µm) with carbonyl iron particles (CIPs) having average particles size of 6 µm. Yield stress of MR fluids is measured using a rheometer. The composition of the fluid has CIPs of 25%, abrasive 10% (by volume) and rest of the base medium (liquid). The yield stress was evaluated at magnetic flux density of 0.33 Tesla. It is observed that MR fluid having the same particle size of CIPs and abrasive particles exhibits higher yield stress as compared to other combinations. The lowest yield stress is observed in case of 9 µm abrasive particles size. A set of finishing experiments is carried out to understand the effect of relative size of magnetic particles and abrasive particles on surface roughness values.

Magnetic Abrasive Finishing (MAF) process is an advanced finishing method involving a dry medium comprising iron and non-magnetic abrasive particles. When this mixture is brought in the magnetic field, it forms a very fine, multiple, and flexible abrasive brushes, which can be used for finishing the magnetic as well as non-magnetic materials such as aluminum. For performing finishing operation on aluminum shaft, novel finishing tool having the fixtures for holding the workpiece and other comprising part have been designed, developed and fabricated. These fixtures are attached to a Lathe machine and moved along the length of the rotating workpiece. The non-magnetic material, which is chosen as aluminum, and the finishing operation is performed on it. Minimum surface roughness 96 nm after the actual surface finish of 400 nm with the change in percentage Ra 76% is achieved using the novel finishing tool.

It is difficult and challenging to achieve uniform nanoscale surface finish in the contact zone, particularly on freeform (or sculptured) surfaces having different curvatures at different locations. Femoral (or, Knee joint component) is one of such biomedical freeform component which has complex profile along its curvature. Surface conditions of a femoral decide the life of the implant and they play a crucial role in its functionality. The variation in surface roughness of the femoral should be minimum in the contact zone. For this purpose, a special tooling is being proposed for rotational magnetorheological abrasive flow finishing (R-MRAFF) process. A negative replica of the workpiece (knee joint) as a tool (or a fixture) is used so that the medium flow velocity in the fluid flow channel is almost constant (or minimum possible variations) along the medium flow direction. It is able to do differential finishing also along the curvature. In addition, pulsating magnetic field has been used to generate vibrations in the medium in the finishing zone so that the possibility of fresh abrasive particles interacting with the surface of femoral is high. The surface finish has been achieved ranging from 26 nm to 62 nm using the proposed finishing technique and negative replica of the workpiece (femoral) as a fixture.