Metal removal in electric discharge machining takes place through

The correct option is melting and vaporization.

Electric Discharge Machining (EDM) is a non-traditional thermoelectric machining process where material is removed from a conductive workpiece by a series of rapidly recurring electrical spark discharges between an electrode (the tool) and the workpiece, which are separated by a dielectric fluid.

The material removal process occurs through the following sequential steps:
1. Spark Initiation: When a voltage is applied across the small gap between the tool and the workpiece, an intense electric field is established, causing the dielectric fluid to ionize and form a conductive plasma channel.
2. Intense Heat Generation: The spark discharge creates extremely high localized temperatures, often ranging from 8000 °C to 12000 °C, at the point of contact on the workpiece surface.
3. Melting and Vaporization: This extreme thermal energy instantly melts and vaporizes a minute volume of the metal on the workpiece surface.
4. Flushing: When the electrical discharge is turned off, the plasma channel collapses. This leads to a sudden drop in pressure, allowing the dielectric fluid to rush in and flush away the molten and vaporized metal droplets, leaving behind tiny craters on the workpiece surface.