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In this paper, the effect of cutting parameters during micromilling on surface finish and material removal rate is presented. Inconel 718 alloy and high-speed steel micro end mill are used as work material and cutting tool, respectively. High-speed steel end mill of 1 mm diameter is subjected to cryogenic treatment. Machining studies are performed on Inconel alloy using untreated and cryogenic treated cutters. The milling tests are conducted at three different values of feed rate, cutting speed and depth of cut. Also, tool wear, microstructure and microhardness of different treated and untreated end mill are investigated and discussed in detail. The results showed that cryogenic treatment significantly improved the tool wear. The surface finish produced on machining the work-piece is better with the cryogenic treated tools than when compared with the untreated tools. The material removal rate is better with the cryogenic treated tools than when compared with the untreated tools. Improvement in tool life was up to 53.16% for Inconel 718 material when machined with cryogenically treated micro end mill.

Surface finish is the most desired properties of any sophisticated machinery parts for its proper functioning and long endurance. The surface finish must be in the order of micrometer to nanometer for most of the machinery parts. The nontraditional surface finish processes prepare these parts; in these processes, the uses of electromagnet play a vital role in the surface finishing mechanism. Magnetic abrasive flow finishing (MAFF) is such a hybrid process, which gives a combined effect of abrasive flow finishing (AFF) and magnetic abrasive finishing (MAF). In this method, a pair of electromagnets are attached to the AFF setup. By using electromagnet in the AFF process, it enhanced material removal and surface finishing. The main process parameters selected in the MAFF process were magnetic flux density, number of cycles, percentage abrasive content, piston speed, and corresponding responses selected were material removal, percentage improvement in surface finish. In this research paper, the responses were optimized by a combination of utility theory and meta-heuristic firefly’s algorithm. The utility theory based-firefly algorithm’s predicted global optimum parameters set, which was more suitable for reducing the finishing time and required surface finish. The confirmatory test validated this optimized parameter set and it was revealed that the meta-heuristic firefly algorithm embedded with utility theory had given optimized results in the MAFF process.

The most critical phase of all the stages needed for quality sample preparation for microscopic study is perhaps surface polishing. Magnetic abrasive polishing is a nonconventional finishing operation that can finish different materials and produce nano-finished surfaces. This study emphasizes the fabrication of a magnetic abrasive polishing setup for metallurgical polishing of specimens. Utilizing this test arrangement, exploratory investigations have been conducted to analyze the impact of five significant interaction factors, specifically the gap between the magnetic pole and the workpiece ($G$), the quantity of diamond-based sintered magnetic abrasives ($Q$), the rotational speed of the magnetic pole (RPM), the grit size of sintered magnetic abrasives ($S$), and machining time ($T$). The abrasives used in this study were diamond-based sintered magnetic abrasives. The percentage change in surface roughness (PCSR) of the stainless steel SS304 workpiece is the response variable. From the results of the ANOVA study, the most important factor affecting the PCSR of the stainless steel SS304 workpiece is the abrasive grit size (49.49%), and the least important factor is the machining time (4.89%). The differences in scanning electron microscopy (SEM) images and surface profiles of workpieces demonstrate that the developed setup can polish stainless steel SS304 plane workpieces.

This paper presents a systematical study on deformation mechanism characteristic and surface quality of high manganese steel during high-speed cutting test using metal ceramic cutter, which was under the condition of dry cutting. The cutting deformation of material was observed from both sides of macroscopic and microscopic scale and analyzed the morphologic feature. The roughness height of the processed surface was measured by digital roughness meter. The roughness data was disposed by means of binary linear regression and obtained a model of surface roughness for high-speed machining. The results show that the macroscopic morphology of chip is overall continuous while the top of it has microscopic serration. The undersurface on chip contacted with tool rake face appears cold welding phenomenon because of high cutting temperature. The fracture property of chip tends up-and-up with the increase of cutting speed. The average prediction accuracy of surface roughness model is 85% or so, which can be used to predict a surface quality or offer the basis for choosing cutting parameters in the high-speed processing.