Applications of EDM Cutting in the Medical Industry
Precision is a life-saving manufacturing requirement in medical parts. Medical components must adhere to details from surgical instruments to implants to ensure high performance and patient safety. This is where Electrical Discharge Machining (EDM) comes in.
EDM cutting is a precision machining process that medical part manufacturers can use to create medical parts with high precision and accuracy. This post will discuss its application in the medical industry and how it shapes modern healthcare.
What is EDM Cutting?
In Electrical Discharge Machining, electrical sparks erode material from a workpiece. This machining technique only works with conductive metal and can shape hard metals that are difficult to machine using traditional machining methods.
Unlike milling, turning, or other traditional machining processes, EDM cutting generates heat and uses electric sparks to melt or vaporize the workpiece. The temperature at the point of contact between the spark and the workpiece can exceed 12,000°C.
Despite these extreme machining conditions, the material removal rate is small (measured in microns), making EDM machining the choice of method for precision CNC machining services since its tolerances can be as small as ±2 microns.
There are several types of EDM cutting. Wire EDM, a technique that uses thin wire (often brass) as the electrode, produces parts with complex geometries. Sinker EDM, which uses a pre-shaped electrode pressed into the workpiece, makes molds for medical tools or devices. Lastly, hole drilling EDM is ideal for creating holes as small as 0.1mm, which makes it applicable in making endoscopic devices.
Applications of EDM Cutting in the Medical Industry
EDM cutting is widely applicable in the medical industry and is highly recommended by many precision machining services. The process can make medical parts that include:
Precision Surgical Instruments
EDM cutting’s main application in medical part manufacturing is the production of surgical instruments like scalpels, forceps, and scissors. These instruments must be sharp and require precision and high tolerance, making EDM machining suitable.
Furthermore, the instruments use hard metals like stainless steel and titanium, making EDM cutting medical parts better because of the compatibility with hard materials, sharpness, and edge retention compared to machining processes.
Implants and Prosthetics
EDM machining also applies to making medical implants, including hip joints, dental implants, and bone plates. These parts are made using biocompatible materials like titanium and cobalt-chrome alloys, which are hard to machine using traditional machining.
EDM cutting services recommend the machining technique because it can meet tight tolerances and maintain dimensional accuracy compared to other machining methods.
Micro-Devices for Minimally Invasive Surgery
EDM cutting can manufacture micro-devices for minimally invasive surgeries, like laparoscopy and endoscopy. The machining process allows precision machining manufacturers to produce tiny components without introducing heat stress.
For example, the micro-laparoscopic instruments used today, which measure as small as 3mm in diameter, owe their precise manufacturing to EDM. Moreover, EDM medical parts are smooth, burr-free surfaces and require minimized post-processing.
Rapid Prototyping for Medical Innovation
With EDM, rapid prototyping is a reality. Prototypes for new medical tools and implants can be produced quickly, allowing medical device manufacturers to iterate their designs efficiently. Using EDM cutting, according to the Medical Device and Diagnostic Industry magazine, can cut the design-to-production timeline by 50%
Pros of EDM Cutting for Medical Parts
High Precision
EDM offers a level of precision that can meet the exacting standards of the medical industry. For instance, it can achieve tolerances as tight as ±2 microns, making it perfect for cardiac stents and dental implants where precision is paramount.
Compatibility with Hard Materials
Titanium, cobalt-chrome, and stainless steel are tough to machine using traditional machining techniques. However, EDM machining can cut through metals with a hardness of up to 75 HRC (Rockwell Hardness Scale), a key advantage over mechanical cutting methods.
Non-Contact Process
EDM is a non-contact process that doesn’t introduce mechanical stresses that could deform fragile components. This is important for medical devices like micro-needles or precision implants that need to maintain exact shapes.
Excellent Surface Finish
EDM can produce surface finishes as fine as Ra 0.1µm, often needed for medical implants that integrate with biological tissues. A smoother surface reduces the likelihood of bacteria accumulation, enhancing biocompatibility.
Cons of EDM Cutting for Medical Parts
Slower Material Removal Rates
EDM is relatively slow compared to traditional methods like CNC machining. For example, while CNC machines can remove material at rates of up to 300 cubic cm/min, EDM averages around 5-10 cubic cm/min. This can make it less suitable for high-volume production runs.
Electrode Wear
The electrodes used in EDM erode during the process, and their constant replacement can increase costs. Electrode wear can account for up to 30% of the overall production cost in sinker EDM.
High Energy Consumption
EDM machines are notorious for their energy consumption, with an average EDM machine consuming around 0.5 kWh per hour. This is significantly higher than conventional machining methods.
Material Limitation
EDM cutting is restricted to electrically conductive materials, meaning this technique cannot process polymers and non-metallic materials.
Conclusion
Electrical discharge machining (EDM) is an invaluable tool in the medical industry because of its precision and ability to machine hard parts, which are expected in the medical manufacturing industry. Over time, EDM has proven its worth.
The precision part manufacturing process also has drawbacks like slower production speeds and higher costs due to electrode wear. However, its advantages make it indispensable for medical manufacturers.
