Krupa Serah Jacob

Bio: Krupa Serah Jacob is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Machining & Electric discharge. The author has co-authored 1 publications.

Effect of micro double helical grooved tools on performance of electric discharge drilling of Ti-6Al-4V:

Abstract: Machining of complex features and holes on superalloys is a topic of both industrial and academic interest. Though the demand for high aspect ratio holes on Ti-6Al-4V is high in aerospace, biomedic...

Simulation of flow-field and debris temperature analysis in micro-electrical discharge milling using slotted tools

Abstract: In micro-electrical discharge milling (μED-milling), the rotation and forward feed motion of the tool is the key element responsible for evacuation of the debris particles. The inability to eliminate debris from the interelectrode gap (IEG) causes secondary discharge, short-circuit, and hampers removal rate. This problem is predominant in electrical discharge machining (EDM) where the tool is stationary. Various methods have been devised in the literature to boost debris removal from the IEG. In this paper, the use of a slotted tool with different cross-sections is proposed. The dielectric flow-field, debris trajectory, and cooling rate are calculated using computational fluid dynamics (CFD). Effect of different parameters such as tool rotation, gap size, jet velocity, the shape of slots on the dielectric flow is determined. The slots on the tool create turbulence which enhances the debris removal from the IEG. It also provides the space to accumulate the debris particles, thereby increasing the removal rate. The variation in the dielectric flow-field greatly affects the debris flushing from the IEG. The trajectory of the debris particles depends on their initial position in the IEG and they cool rapidly, which is validated using simulation and mathematical approach.

Study on machinability of three-step drill in drilling Ti6Al4V

Abstract: As the research progresses, titanium alloy materials have more applications in aerospace and other fields. However, problems such as chip winding and serious tool wear are easy to occur in the machining process. In this research, the three-step drill has changed the main cutting-edge structure, which is more conducive to chip breakage. Firstly, the drilling force of the three-step drill bit is analyzed, and the alternating stress that makes the chip thickness change is obtained by the cutting-edge structure of the three-step drill bit. The simulation and experiment are verified by each other, and the feasibility of three-step drilling to improve the processing quality is obtained. The results show that the improved drill has good chip breaking performance, low thrust force, and better machining performance compared with the twist drill. In addition, the improved drill can obtain a more complete inner wall of the hole and reasonably improve the surface quality. Through experiments, it is found that changing cutting parameters such as feed rate has different effects on chip thickness, thrust and tool wear. It was found that the drilling force was reduced by drilling Ti6Al4V material with the three-step drill. Moreover, the three-step drill can produce smaller chip thicknesses and make the chip more prone to breakage when compared with the twist drill. The high wear of three-step drill bits can also be better weakened by coating materials.