Wire Electrical Discharge Machining (EDM) relies on two primary processing media: pure water and oil. This article delves into the distinct characteristics of these fluids, their impact on machining precision, and their applications in various industries.
During wire EDM, the generation of frictional heat poses challenges to maintaining dimensional accuracy and surface quality. Utilizing pure water as a processing medium proves beneficial in addressing these concerns. Not only does pure water effectively reduce the wire's operating temperature, preventing deformation, but it also extends the machine's service life.
The cooling properties of pure water play a pivotal role in improving workpiece quality. By carrying away heat and debris during the machining process, pure water prevents adverse effects on the machine tool. Additionally, its lack of hardness substances and harmful ingredients minimizes the risk of corrosion and dirt accumulation on both the workpiece and the machine tool equipment.
However, it's essential to note that workpieces submerged in water may be susceptible to rust. The cut surface may develop a soft oxide layer, which, if worn off during use, can impact dimensional accuracy. Despite these considerations, pure water remains a popular choice for various applications.
In contrast, machining with oil as a processing fluid is ideal for hard alloy parts demanding ultra-precision, often reaching accuracy levels in the nanometer range. Immersing the workpiece in oil not only enhances precision but also shields it from corrosion.
While the cutting speed of the oil line is relatively slow, its unparalleled accuracy and smoothness create a mirror effect on the machined surface. With a machining precision of +/- 0.002mm and a surface roughness reaching 0.05Raμm, Rz0.1, oil-based wire EDM achieves exceptional results in terms of precision and finish.
Wire cutting machines, especially the typical slow wire cutting machines, offer versatility in processing media. They can utilize pure water, oil, or a combination of both based on specific requirements. However, it's crucial to consider the cost implications, as oil wire cutting machines are approximately four times more expensive than their water counterparts.
Despite the cost difference, oil-based wire cutting machines find widespread use in industries demanding top-tier precision. They are commonly employed in telecommunications, computers, electronic components, aviation, and medical devices, where the need for ultra-precision machining outweighs the associated expenses.
In conclusion, understanding the nuances of pure water and oil as wire EDM processing media is pivotal for making informed decisions in CNC machining processes. The choice between the two depends on specific application requirements, precision needs, and budget considerations.