Spark Erosion Services

Spark erosion services offer the machining of hardened conductive materials by using a concentrated spark to cut away at the workpiece, otherwise known as electrical discharge machining. During the spark erosion process, an electrode of varying shape and a conductive workpiece are immersed in a dielectric fluid. As the electrode nears the workpiece, a spark jumps between the two, creating a hot plasma on the surface of the workpiece that cuts it in a shape opposite to that of the electrode.

A spark erosion machine facilitates and contains the process of spark erosion. Spark erosion machines can be portable for the access of onsite or stationary machinery. The spark erosion machine contains the electrode and the dielectric fluid necessary for the process, so that chippings can be flushed from the workpiece.

A dielectric fluid is capable of insulating an electric force, meaning it can transmit a spark between the electrode and workpiece precisely. This fluid often takes form as an oil or deionised water.
The dielectric fluid moreover helps flush chippings from the workpiece as well as protecting the electrode from excessive wear.

The intricate nature of the spark erosion process means it can be used for stud removal. Spark erosion can be utilised to gain access into complex machinery for the replacement or removal of studs or bolts, without needing to dismantle or replace the machine. Small pieces of machinery surface can be removed at the point of access, so that direct entry, with minimal impact, can be achieved and a new stud or bolt can be fitted.

Another utilisation of spark erosion is for grinding, where the spark erosion process replaces a traditional grinding wheel. During spark erosion grinding, a workpiece coated in dielectric fluid is rotated by a lathe, as an electrode is lowered near it; a spark is then generated between the two, which cuts the workpiece, removing excess or unwanted surface material.

Various materials can be used for the spark erosion electrode, providing they’re conductive. Brass, copper, graphite, and tungsten are all used, and spark erosion electrode material should be selected based upon the requirements of specific applications. For instance, brass was the first electrode material used in the spark erosion process, but was replaced by copper for its improved conductivity. Graphite works well in extremely hot temperature ranges, and tungsten is used in cases where strength is desired, though this is not a common choice.

Spark erosion speed is determined by the material of the electrode and the workpiece. The transmission of a spark happens around 10,000 times a second, though frequency will vary depending on the application.

Spark erosion advantages include: the machining of both hardened and delicate materials; no contact between the electrode and workpiece is required, therefore delicate pieces can be machined without damage or distortion. Spark erosion is also precise, and tight tolerances can be achieved. A good surface finish can also be attained.

Spark erosion disadvantages include: the workpiece must be of a conductive material to successfully machine. Workpieces are best machined when supported during the process, otherwise surface deformity may occur. The spark erosion process requires great power consumption and can wear tooling quickly.

Generally, a good surface finish can be achieved. However, spark erosion surface finish can be affected by several factors, including the frequency of the machine (a higher frequency creates a smaller spark to attain a better surface finish) and the material of the electrode.