Selecting the right finishing treatment for precision machined parts can be overwhelming—there are so many options to choose from, each with their own unique characteristics. Today, we’re demystifying a lesser-known but ideal treatment for many stainless steel parts: electropolishing.
Electropolishing is an excellent choice for certain aerospace and medical applications. Although the technique isn’t new, it’s underutilized compared to other finishing methods, despite creating one of the smoothest, most brilliant finishes possible.
How Does Electropolishing Work?
Electropolishing (also referred to as reverse electroplating) applies electric current to a part to dissolve an outer layer of iron into an electrolyte solution. The process etches away up to 50% of microscopic surface imperfections (such as burrs), provides a deep clean, and gives parts a lustrous finish.
Customers sometimes request both electropolishing and passivation for their stainless steel parts. But here’s a little secret: passivation is actually achieved through the electropolishing process, so you can reap the advantages of both finishing operations with electropolishing alone.
6 Reasons to Choose Electropolishing
Here are six reasons to consider this often-overlooked finishing method for your stainless steel parts:
1. Brilliant finish
Because electropolishing produces a high shine, the technique is ideal for applications requiring a superior cosmetic appearance. It’s also cheaper and more environmentally friendly than other high-shine finishing options such as chrome plating.
2. Frictionless surface
Certain applications demand a completely smooth surface that is free of microscopic imperfections. Fulfilling this requirement is particularly important in aerospace machining, where micro burrs on parts can cause water or air to “catch” and create turbulence.
Smooth surfaces are also easier to keep clean, making electropolishing a natural choice for medical and food service applications in which sanitization is paramount.
It’s important to note, however, that electropolishing can only achieve optimal smoothness on a microscopic level. If your part has deep scratches or other substantial imperfections, electropolishing will make them less noticeable but won’t remove them entirely.
3. Compatible with tight tolerances
With electropolishing, material removal can be controlled to between 0.0001” and 0.0002”. That’s a highly precise range compared to other treatments like anodizing, which can cause significant buildup and throw parts out of tolerance.
For this reason, electropolishing is an excellent solution for parts with tight tolerances.
4. Enhanced corrosion resistance
The highly corrosive iron content in stainless steel typically overrides the anti-corrosive effects of chromium and nickel, which are also present in the material. Electropolishing strips the free iron from a part, enabling the chromium and nickel to become dominant and strengthening corrosion resistance.
Keep in mind, however, that the degree of corrosion resistance varies depending on the stainless steel alloy you’re using, so be sure to consult with our team if your part will be in a highly corrosive environment.
5. Suitable for parts with complex geometries
Complex parts are often difficult to deburr due to variations in surface depth. Electropolishing chemically etches peaks down to create an even surface, a feat that many alternative treatments cannot accomplish.
6. Detects flaws
If there’s a flaw beneath the surface of your part, electropolishing will find it. The powerful chemicals in the electrolyte solution act as a sort of “truth serum,” revealing any hidden problems that could compromise your part’s performance.
Choose Reata Engineering for Electropolishing Services
If electropolishing sounds like the perfect solution for your precision machined parts, we can obtain this service on your behalf via a supplier in our trusted network. As a single-source solution for your precision machining needs, Reata Engineering aims to optimize the customer experience, which includes coordinating finishing services.
Our strong project management capabilities ensure that parts move seamlessly from our precision machine shop to a well-vetted finishing shop, yielding final results that will exceed your expectations.
Request a quote today to get your project started!