Molybdenum Electrodes

Electro Arc’s Metal Disintegrators and Spark Erosion Machines can use any material that conducts electricity as an electrode. However, different materials offer varying levels of efficiency in the process. It is important to use an electrode material that breaks down less than the work piece. Materials with low melting points, such as copper, erode as rapidly as the work material, requiring frequent replacement, which adds to your cost. Copper electrodes will get hot. With heat they will bend and warp damaging the hole. Due to their high melting temperature outperforming other electrode materials, we recommend and provide Molybdenum electrodes in a variety of shapes and lengths.

For Molybdenum Electrodes the diameters start at .020″

Graphite Electrodes

Graphite has several advantages over other materials. It is resistant to thermal shock. It is the only material in which mechanical properties increase with temperature. It has a low CTE for geometrical stability. It is easily machined. It does not melt but sublimes at very high temperature (3,400ºC), and finally, its density is lower (five times less than copper) which means lighter electrodes. Graphite removes material better than copper or copper-tungsten while wearing slower. The wear rate tends to diminish as the discharge increases, unlike copper, whose wear increases at higher currents. Therefore, graphite is suited for the machining of large electrodes since working with a high current intensity provides decreased roughing time.

Although graphite is prone to abnormal discharge, this can be eliminated through quality flushing, and lowering the intensity of discharge during negative polarity machining. However, as a result of this tradeoff, machining tungsten carbides is more difficult than with copper-tungsten electrodes. Also, since graphite is a ceramic, it is sensitive to mechanical shock, and consequently must be handled and machined with care.

For Graphite Electrodes the diameters start at 3/8″(9.5 mm)

For Graphite Electrodes the minimum power supply requirements are 15 KVA or higher