Spark Erosion Explained

When dealing with difficult materials or complex shapes and sizes, spark erosion is one of the most successful forms of machining. There are no cutting forces so the integrity of the material is always maintained.  The process is highly controlled and allows for proper removal of material even on delicate materials.

How does Spark Erosion Work?

To begin the process, you need two things. The first is the metallic piece you will be working on. The piece can be made from aluminium or steel. The second one is the electrode. The shape of the electrode does not matter. You can opt for one that shaped like a cylinder or go for more complex shapes like a polygon or a diaphragm.

Once you have chosen your electrode of choice, it is mounted on the machine and it is aligned with the travel direction.  The process can begin after the alignments have been double-checked to make sure everything is correct.

The piece being worked on is soaked in a dielectric liquid. The machine is fitted with state of the art motion electronics and hydraulics. These allow the electrode to move closer to the workpiece. This produces sparks that move between the workpiece and the electrode gently cutting through the workpiece. A puddle is created by the spark (also known as the hot plasma) as a result of the workpiece being melted by the electrical discharge produced by the electrode. The small amount of dielectric is vaporised which creates bubbles around the spark. On average, this process is repeated over 10,000 times per second.

It is important to keep the work area clean. A slower removal rate increases the rate of tear which is related to the rate of removal. The head is located in the flush area which helps to speed up the time for metal removal. The result of the removal also affects the size of the spark. Big and long sparks lead to a bigger depth and a rougher surface. For a finer finish, smaller sparks, a higher wear rate and low removal rate are required. There are copper alloys that have been designed to maximise the process of spark eroding and offer better wear resistance and improved machinability.

Sodick Wire EDM

Here at MNB Precision, we have the Sodick Wire EDM which is one of the best machines that the industry has to offer. One of the features that make it such an important part of machining is the automatic tool changers. These allow the machine to not only work fast but also very accurately. It is particularly handy when handling different projects like the US Oil and Gas company.

The spark erosion machining process can be used by different industries in different fields including those in;

• Nuclear
• Gas and Oil
• Aerospace

Spark eroders are highly efficient machines that are ideal in machining complicated materials and shapes and are able to capture precise details of even the hardest materials.