Spark Erosion

Spark erosion, also known as Electrical Discharge Machining (EDM), is a non-traditional machining process that removes material from a conductive workpiece by generating controlled electrical sparks. These sparks are discharged between an electrode (tool) and the workpiece, creating intense heat that melts and vaporises small amounts of material, precisely shaping the workpiece without direct contact.

Key Characteristics of Spark Erosion

• Material Removal
  Material is removed through rapid electrical discharges that generate temperatures high enough to melt and vaporise localised areas of the workpiece.

• Non-Contact Process
  Since the electrode does not physically touch the workpiece, spark erosion is ideal for delicate parts and complex shapes that might be challenging to machine with conventional methods.

• Use of Dielectric Fluid
  The process typically involves immersing the workpiece and electrode in a dielectric fluid (usually deionised water or oil). The dielectric fluid helps control electrical discharge, cool the workpiece, and flush away eroded particles.

Types of Spark Erosion

• Sinker EDM … uses a shaped electrode that is “sunk” into the workpiece, creating cavities or complex shapes.

• Wire EDM … utilises a thin wire as the electrode to cut intricate shapes and profiles in the workpiece, often for components like gears or dies.

Applications of Spark Erosion

• Tool and Die Making … is commonly used to produce moulds, dies, and complex cavities with intricate details.

• Aerospace and Medical … ideal for machining hard-to-cut materials like titanium or for creating fine features in medical implants.

• Micro-Machining … allows for precise material removal on very small components that require exact tolerances and fine finishes.

Advantages of Spark Erosion

• Precision and Accuracy … can achieve tight tolerances and intricate details, even on hard materials.

• Complex Geometries … capable of creating shapes that are difficult or impossible with conventional machining methods.

• Minimal Tool Wear … since there is no direct contact, the electrode experiences little wear, maintaining a consistent shape over prolonged use.

Spark erosion is a precise, non-contact machining process that removes material from conductive workpieces through controlled electrical discharges. Ideal for complex shapes and tough materials, spark erosion is widely used in industries that require high precision, such as toolmaking, aerospace, and medical device manufacturing.