Electric Spark Machining
The process of Electric Spark Machining (ESM) is a machining process in which an electrical arc is used to remove material from a workpiece. This process involves a non-contact form of thermally assisted machining, making it a viable option for delicate and intricate workpieces. This process is highly efficient for cutting, grinding, and deburring difficult machining processes. It is also capable of machining difficult-to-machine materials such as stainless steel, hardened steel, titanium, and aluminum alloys.
The process of ESM is a variant of electro-discharge machining (EDM) but with a few slight differences. The main difference between the two processes is that, while EDM involves using a dielectric fluid to dissipate the electrical spark, ESM does not require this additional step, reducing the expense and complexity of the process. Additionally, where EDM generally requires greater cutting force, ESM is limited in its thrust strength, making it a lower force alternative.
The setup for an ESM process could not be simpler, requiring only the power source, an electro spark generator, and the workpiece. A low-voltage and high-current electrical power source is required, which is connected to the electro spark generator, which in turn is responsible for generating the electrical arc needed to cut away the material. This arc is actually a short and intense burst of current which is used to vaporize or heat away the material being worked on by the power source.
The ideal process parameters for ESM are generally higher than those required for conventional machining processes. The current range used in the process is usually between 10 and 500 amps, depending on the size and desired finish of the workpiece. The current is also usually delivered at a high frequency, usually over 200 kHz and up to 500 kHz, depending on the size and shape of the workpiece. The pulse duration is typically between 0.1 and 1.0 milliseconds, and the process time can range from one to several minutes, again depending on the complexity of the workpiece.
One of the major benefits of ESM is its ability to perform high-precision machining. Since the sparks are delivered in short pulses, the process is capable of creating intricate shapes and finer surface finishes than other machining methods. Additionally, the process is extremely fast, due to the short pulses, and is capable of reaching up to 600 pulses per second.
This process is extremely safe, with minimal vibration and no hazardous waste produced. Additionally, it is capable of machining workpieces which are both hard and soft. This makes it an ideal method for machining medical, dental and precision parts where a high level of tolerance, accuracy, speed and safety are required.
Overall, electric spark machining is a great choice for machining hard-to-reach areas, intricate geometries, and workpieces which require very fine surface finishes. Its low-force cutting, low-vibration operation and environmental safety also make it a great choice for medical, dental and precision parts.
