A systematic review on powder mixed electrical discharge machining

Abstract

The advancement in the field of material science has gifted us new electrically conductive materials having good mechanical properties and thermal characteristics. Machining these materials using conventional machining process is a challenging task. Electrical discharge machining (EDM) is a well-established machining process used to manufacture process hard materials having geometrically complex shapes, that are extremely difficult to machine traditionally. EDM is a thermo-electric process in which material is eroded by rapidly recurring sparks between the non-contacted electrode and workpiece. As there is no direct contact between the electrodes in EDM, machining defects like mechanical stresses, clattering & vibration do not create problems during machining. In spite of the advantages of the process, its use in industry is limited owing to poor surface finish and low volumetric material removal. To overcome these drawbacks, the metallic powder is mixed in the dielectric fluid, which increases its conductive strength and increases the spark gap distance between the tool and workpiece. This new evolved material removal process is called Powder Mixed Electrical Discharge Machining (PMEDM). The added powder significantly affects the performance of the EDM process. The objective of this review is to benefit the researchers to understand the PMEDM concept precisely and study the process parameters furthermore in particulars to get enhancements in the process to achieve better quality levels.

Parametric Optimization and Effect of Nano-Graphene Mixed Dielectric Fluid on Performance of Wire Electrical Discharge Machining Process of Ni55.8Ti Shape Memory Alloy

“…Figure 5 depicts that SR of machined surface decreases with the increase in Nano-powder concentration. Insulating strength of dielectric fluid decreases after adding powder concentration in dielectric fluid which in turn increases the conditions of inter-electrode gap [ 18 ]. Thus, this increase in inter-electrode gap condition improves the performance by obtaining superior surface finish [ 18 ].…”

“…Insulating strength of dielectric fluid decreases after adding powder concentration in dielectric fluid. It further increases the inter-electrode gap condition [ 18 ]. Thus, this increase in inter-electrode gap condition improves the performance by obtaining superior surface finish.…”

“…Recently, powder-mixed dielectric fluid has turned out to be popular among the researchers to obtain optimum parametric setting for multiple objectives such as MRR and SR. Different powders such Si, W, Al, SiC, Cr, Ti, CNT, Al 2 O 3 , Gr/C, Mo, and Cu have been used by researchers which has been diluted with dielectric fluid for EDM process [ 18 , 22 ]. Important powder characteristics such as size of powder, concentration, thermal and electrical conductivity, and powder density have significant effect in process.…”

Multi-response optimization for Nimonic alloy miniature gear fabrication using wire electrical discharge machining

“…When low strength dielectric constituents are added to the DM water, the overall dielectric strength of the dielectric fluid is reduced, which results in less and uniform spark energy, and which produces associate effects on machining characteristics of the miniature gear. 48 Table 2 shows the dielectric strength of the constituents.…”

Investigation of Surface Quality in Cost of Goods Manufactured (COGM) method of µ-Al2O3 Powder-Mixed-EDM Process on Machining of Ti-6Al-4V

“…The addition of conductive powders can reduce the resistance of dielectric fracture to reduce the machining time with better surface quality in PMEDM process [16][17][18] . This has created considerable research directions to improve the machinability of titanium alloy in PMEDM process.…”