Electrical discharge machining (EDM) is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process to a micro-scale application machining alternative attracting a significant amount of research interests. In recent years, EDM researchers have explored a number of ways to improve the sparking efficiency including some unique experimental concepts that depart from the EDM traditional sparking phenomenon. Despite a range of different approaches, this new research shares the same objectives of achieving more efficient metal removal coupled with a reduction in tool wear and improved surface quality. This paper reviews the research work carried out from the inception to the development of die-sinking EDM within the past decade. It reports on the EDM research relating to improving performance measures, optimising the process variables, monitoring and control the sparking process, simplifying the electrode design and manufacture. A range of EDM applications are highlighted together with the development of hybrid machining processes. The final part of the paper discusses these developments and outlines the trends for future EDM research.

http://zclient.persiangig.com/ScienceDirect/M02.pdf

State of the art electrical discharge machining (EDM)

Steels for bearings

Tool Condition Monitoring (TCM) — The Status of Research and Industrial Application

Friction stir welding (FSW) is a widely used solid state joining process for soft materials such as aluminium alloys because it avoids many of the common problems of fusion welding. Commercial feasibility of the FSW process for harder alloys such as steels and titanium alloys awaits the development of cost effective and durable tools which lead to structurally sound welds consistently. Material selection and design profoundly affect the performance of tools, weld quality and cost. Here we review and critically examine several important aspects of FSW tools such as tool material selection, geometry and load bearing ability, mechanisms of tool degradation and process economics.

Review: friction stir welding tools

https://escholarship.org/content/qt7hd8r1ft/qt7hd8r1ft.pdf

Advancing Cutting Technology

Tool-wear mechanisms in hard turning with polycrystalline cubic boron nitride tools

A 100Cr6 (AISI E52100) steel in the hardness range of 180 to 750 HV 16 was machined, Quick stop tests were carried out at various hardness values to observe the different chip formation mechanisms. A limit was found between the shearing and cracking chip formation. Experiments on the selected steel at 750 HV 10 were carried out at various cutting speeds and feed rates. The saw tooth chips obtained were examined geometrically and metallurgically on longitudinal midsections. A relationship has been established between the chip geometry and the cutting conditions. A theoretical study of the chip shape was made, in particular its thickness. The friction stick slip velocities, and the segment apparition frequency were calculated. Each stage of the chip formation could be observed on each micrograph of Q.S.T, especially the crack initiation. A discussion on the apparition of the thin white layers is also proposed.

Hard Turning: Chip Formation Mechanisms and Metallurgical Aspects

A Study of the Effect of Synchronizing Ultrasonic Vibrations with Pulses in EDM

On modelling the influence of thermo-mechanical behavior in chip formation during hard turning of 100Cr6 bearing steel

https://hal.archives-ouvertes.fr/hal-01133716/document

A. Moisan

Papers

Tool-wear mechanisms in hard turning with polycrystalline cubic boron nitride tools

Hard Turning: Chip Formation Mechanisms and Metallurgical Aspects

A Study of the Effect of Synchronizing Ultrasonic Vibrations with Pulses in EDM

On modelling the influence of thermo-mechanical behavior in chip formation during hard turning of 100Cr6 bearing steel

Precision and surface integrity of threads obtained by form tapping