ABSTRACT
Thermoelectric processes where the metal removal rate depends upon the thermal energy acting in the form of controlled and localized power pulses leading to melting and evaporation of the work material. This chapter deals with these processes, such as electrical discharge machining (EDM), laser and electron beam machining (LBM and EBM), and plasma arc cutting (PAC). The capabilities, advantages, and limitations of such processes are examined in this chapter.
EDM is based on erosion of metals by spark discharges between a shaped tool electrode and a workpiece electrode. EBM is a thermal NTM process that uses a beam of high-energy electrons focused to a very high power density on the workpiece surface causing rapid melting and vaporization of its material. A high voltage, typically 120 kV, is utilized to accelerate the electrons to speeds of 50 to 80% of light speed. Laser is a versatile tool. Its effectiveness lies in its ability to deliver, in some cases, a tremendous quality of highly concentrated power. Tuning the laser beam makes it possible to deliver just the right concentration of power for the right amount of time to perform a specific piece of work. PAC is used for rapid cutting of non-ferrous and stainless-steel plates. MRRs are much higher than in the previous thermoelectrical processes.
