Electric Discharge Grinding of Polycrystalline Diamond Materials

Abstract

The poor electric conductivity of polycrystalline diamond (PCD) makes it difficult to machine with the conventional EDM process. Inappropriate selection of parameters of the power generator and the servo system leads to unstable working condition and low material removal rate. This paper introduces a method to find optimal parameters in the Electrical Discharge Grinding (EDG) of PCD materials with Taguchi method. The theory and detailed procedures are presented, experimental results are analyzed. The optimized configuration was validated through confirmation tests.

Electrical discharge machining of polycrystalline diamond: A review

“…It can be seen from the equation that the increase of pulse duration and machining current has a positive contribution to the increase of discharge energy, leading to greater energy for melting and gasification of workpiece materials, thereby improving the material removal rate of EDM. In electrical discharge machining PCD materials, 62–66 the typical relationship between pulse duration and crater radius is shown in Figure 4. Wang et al 67 extended the pulse duration to 1900 μs to further increase the MRR of PCD.…”

Comparative Study of Ultrasonic Vibration-Assisted Die-Sinking Micro-Electrical Discharge Machining on Polycrystalline Diamond and Titanium

“…However, it is difficult to machine PCD by mechanical methods [9]. Due to the poor conductivity of PCD, achieving a higher material removal rate (MRR) in micro-EDM of PCD material requires careful selection of appropriate machining parameters [10,11]. Yan et al [12] designed a novel pulse generator that generated high-frequency pulse signals with an off-time period, enabling the reionization of dielectric in the machining gap, minimizing damage to the machined surface of PCD.…”

Residual Stress Analysis of Polycrystalline Diamond after Electrical Discharge Machining

“…Polycrystalline diamond (PCD) is produced by sintering the selected grades of diamond particles under a pressure of 6000 MPa and at a temperature of 1400°C together with a catalyst metal such as Cobalt, which helps the inter-grows process of sintering by filling all voids left within the structure and ensures the conductive characteristic of PCD [3]. Diamond grain size is the main factor that determines the mechanical properties of PCD, and it is usually in the range between 1 to 80 µm.…”

“…PCD is being used in machining Aluminium alloys in automotive and aerospace industry as a turning, milling and boring tool. It will be graphitized when it is exposed to more than 650° C especially when it is in contact with group VIII metals such as Iron and Nickel [3]. Application of PCD is not only restricted to mechanical engineering, it can also be used as a high temperature electrical or optical devices.…”