C. Sathiya Narayanan

Optimization of EDM Parameters on Machining Si3N4–TiN Composite for Improving Circularity, Cylindricity, and Perpendicularity

The dominance of the spark eroding process in complex ceramic components has promoted a significant growth analysis in the ceramic composites domain in modern manufacturing industries. The latest developments in ceramic components are concentrated on both the enhancement of the mechanical properties and the machinability of complex 3D parts while using spark EDM. The current (I), pulse on time (Ton), pulse off time (Toff), and dielectric flushing pressure (DP) are considered sparking parameters for the machining of a Si3N4–TiN ceramic composite. These composites find their application in high-temperature environments, viz. metal forming, extrusion dies, turbine blade, and non-ferrous molten metal handling components. Taguchis orthogonal array (OA), L18, has been used to design the experiments. The optimal machining inputs are determined by the grey relational grade (GRG), which is attained from the grey relation analysis (GRA) for various response characteristics, such as the material removal rate (MRR), tool wear rate (TWR), circularity (CIR), cylindricity (CYL), and perpendicularity (PER). The significant parameters are identified via an analysis of variance (ANOVA). Finally, the optimized process parameters resulting in a higher MRR, lower TWR, lower form tolerance, and decreased orientation tolerance are verified through a confirmation test demonstrating that sparking process responses can be effectively improved.

Analysis of Form Tolerances in Electrical Discharge Machining Process for Inconel 718 and 625

This article presents an experimental work and investigation on electrical discharge machining (EDM) of Inconel 718 and 625 superalloys. These superalloys are used for making parts like turbine blades, marine components, and nuclear reactor components. The precise components made up of superalloys which have cylindrical, square, and hexagonal machined features are required regular estimations of cylindricity, circularity, perpendicularity, and parallelism. In this work, EDM of the above said superalloys was carried out and form tolerances were analyzed. The significance of input parameters namely peak current, pulse-on time (T on), and pulse-off time (T off) on the form tolerances were investigated. In addition to these, the influence of individual parameters were also analyzed by analysis of variance (ANOVA) technique.

Optimization of Process Parameters to Improve Form and Orientation Tolerances in EDM of MoSi2-SiC Composites

In this research, an investigation and experimental work were carried out on electric discharge machining (EDM) of intermetallic base MoSi2-SiC ceramic composite with copper electrode. It is extremely difficult to machine MoSi2-SiC composite using conventional machining techniques. However, it can be easily machined by executing spark EDM parameters to induce the correct optimum result. These composites find their application in high-temperature environments, viz. fuel turbo pump rotors, inlet nozzles, combustion chambers, injectors, nozzle throats, and nozzle extensions. The sparking parameters, namely current (I), pulse on time (Ton), pulse off time (Toff), spark gap (SG), and dielectric pressure (DP), were investigated by L18 orthogonal array. The optimal process parameters were determined by the grey relational grade (GRG) obtained through the grey relational analysis (GRA) for multiple performance characteristics, viz. material removal rate (MRR), electrode wear rate (EWR), circularity (CIR), cylindricity (CYL), and perpendicularity (PER). The significant process parameters were obtained by analysis of variance (ANOVA) based on GRG, which showed current, pulse on time, and DP. The results were finally established using a confirmatory experiment, which showed the spark eroding process could effectively be improved.

FLD and Fractography Analysis of Multiple Sheet Single Point Incremental Forming

The single point incremental forming (SPIF) process is gaining importance in academic, research and industrial sectors due to its inherent advantages over conventional sheet metal forming processes, viz., high formability, non-dependence on dies and process simplicity. Hence, the process is highly recommended for rapid prototyping applications, but the slowness of the process is a major disadvantage that prevents industries from implementing it on a wider scale. The possibility of using low thickness multiple sheets in a SPIF process is explored in this paper, and the results show the mechanism of sheet failure, new surface generation and the extent of achievable forming limits from the top sheet to the bottom sheet while forming multiple sheets together.

Strain limit of extra galvannealed Interstitial-Free and bake hardened steel sheets under different stress conditions

The formability of bake hardened steel (thickness 0.82 mm), and the extra galvannealed IF steel (thickness 0.82 mm) have been studied. The suitability of the above steels for forming applications has been critically examined. The microstructure, tensile properties, and formability parameters of the above sheet metals were determined. The manufacturing process of the steels and the significance with reference to its formability were studied.

Effect of annealing on forming limit diagram and crystallographic textures of aluminium 5086 grades annealed at four different temperatures

Abstract The crystallographic texture and formability of aluminium alloy 5086 annealed at 160, 200, 250 and 300°C have been studied. Experimentally determined forming limit diagrams (FLDs) for the above said Al 5086 sheets, their crystallographic textures and their orientation distribution function plots made by X-ray diffraction were analysed. The present study shows a comparison between these FLDs of Al 5086 sheets and the corresponding result of crystallographic texture analysis. The FLDs and crystallographic textures were then correlated with normal anisotropy of the sheet metal. It was found that aluminium alloy 5086 annealed at 300°C possessed good formability, preferred texture and high normal anisotropy value.