Why Do I Need Ceramics for EDM?

Electrical Discharge Machining has always been about maintaining high precision. This means building a machine that is largely immune to temperature fluctuations. For many machine builders, a low cost solution has been the use of reinforced plastic insulators between the head and the EDM electrode, as well as elsewhere. However, due to the tendency for these insulating materials to expand and contract with ambient temperature, shops can often see problems such as changes in the center position of a Wire EDM workpiece or inconsistent Sinker EDM discharge. New materials beyond the basic steels and insulators were required, setting Sodick on its path to Ceramics.

Alumina based ceramics are one of the "wonder materials" of the 21st century, with crystal alumina being the primary ingredient lending strength to sapphire. Introducing this high-strength insulating material into a machine provides significant improvements with regard to stable machining environments. With less than 1/3 the thermal distortion of steel and greater corrosion resistance than stone, Ceramics are the most reliable option for high-precision applications.

Ceramic EDM Components


The first and most critical ceramic components in an EDM are the head and the table, which most directly impact the accuracy held during temperature fluctuations. At face value this makes a lot of sense: the table holds the workpiece in position while the head affects the position of the electrode. Shifts in either location can negatively impact the accuracy of a part throughout the machining process. After having great successes with ceramic components, we rolled out more ceramic materials across various Wire and Sinker EDM parts, including upper and lower arms, table pedestals, rollers, and more.

Special Note: EDM Insulation


In addition to thermal insulation, EDM equipment requires insulators that are equally effective at insulating electrical currents. Poor insulation can allow electrical discharges to diffuse through the machine head, dampening the machining process and leading to slower cutting speeds. With proper electrical insulation, discharge currents remain focused from the electrode into the workpiece for highly reliable cutting performance. This makes investment in ceramic components a strategic pillar for Sodick, and is the reason Sodick owns its own ceramics production facility for full vertical integration.

For more information about how ceramic insulation can improve your machining performance, contact your local Sodick representative or simply email sales@sodick.com