Electropolishing
Electropolishing at a glance
Electropolishing is a proven process for surface finishing of metals.
If smoother, shinier or passivated metal surfaces are required for technical or decorative reasons, electropolishing is often used in industry. As an ablative manufacturing process, it is based on the fact that roughness peaks and edges are preferentially removed during the anodic dissolution of metal.
Although plasmotion does not offer electropolishing, it does offer the environmentally friendly and efficient alternative of plasma polishing.
Your expert for questions
- Sven Friedemann
- Technical sales
- Phone +49 3731 37736 - 31
What is electropolishing?
Polishing and deburring through targeted, electrochemical metal dissolution.
Electropolishing is the logical counter-step to electroplating. The metal on the surface of the workpieces is electrochemically dissolved in a bath of material-specific electrolytes - preferably on protruding areas such as roughness peaks. The result is a smoothed, cleaned and polished surface.
Electropolishing of stainless steel has become the standard process for sensitive components, particularly due to the associated passivation and simplified cleanability. In contrast to other surface finishing processes, electropolishing allows finishing without mechanical and thermal stress.
Areas of application for electropolishing
Surface finishing by electropolishing is used in various industries.
Smooth is not always smooth. Due to the ease with which large workpieces can be handled and the freedom to process different geometries without major set-up work, electropolishing has rightly proven itself in a wide range of applications. Electropolished surfaces are characterized by a combination of functional and decorative properties, which is essential for components in medical technology, in food processing plants and, for example, in clean rooms. Here in particular, materials such as 1.4301 and 1.4404 are used almost exclusively, making the electropolishing of stainless steel the most important industrial application.
Industries
Electropolishing ensures smoother and shinier surfaces.
Surgical devices, implants and the like require a smooth, clean surface. Electropolishing is a proven solution here.
Due to the improved cleanability of the surfaces after electropolishing, the technology is used here as standard.
Hygiene is essential when processing food. Electropolished surfaces are smooth and therefore easier to keep germ-free.
When durable and precisely manufactured components are required, electropolishing is a popular surface treatment option. Polishing increases corrosion resistance and can therefore have a positive impact on the service life of components.
An electropolished surface also offers many advantages for jewelry and watch movements.
This form of metal finishing is useful for optimizing the aerodynamics of individual components by reducing roughness. Conventionally manufactured components thus achieve service life specifications and additively manufactured components an improved surface that brings them closer to qualification specifications.
Electropolishing in action
Anodic metal dissolution for high-quality stainless steel surfaces.
Electropolishing can be implemented from individual part production to mass production (barrel electropolishing). The working principle always remains the same. Despite the theoretical flexibility, one variant has clearly established itself: processing in large immersion tanks of usually 2 to 12 cubic meters. Here, highly concentrated mineral acids are used as electrolytes. Due to the associated handling difficulties and health and safety issues, a broad, regional contract manufacturing industry has developed.
The process behind electropolishing
Electropolishing uses anodic metal dissolution to refine metal surfaces.
Electropolishing is based on electrochemical principles - the electrolytic reaction between the metal surface, the electrolyte solution and the process tank. Material-specific solutions are used as the electrolyte, typically highly concentrated mineral acids (phosphoric acid, sulphuric acid, but also others), to which alcohols and surface-active chemicals are sometimes added.
Both metal components become electrodes here: The workpiece acts as the anode, while the process tank forms the counterpart as the cathode. Connected by the electrolyte, they form an electrochemical cell to which a polishing voltage of around 20 V is applied. This results in a targeted, electrochemical dissolution of a thin surface layer of the material, which preferably takes place wherever surface features protrude. These are in particular roughness peaks, burrs and sharp edges. Over time, these features are reduced, resulting in a rounding of the previously fissured microstructure and a rounding of edges. The result: the surface becomes smoother, starts to shine and is cleaned. The real surface can be significantly reduced by electropolishing, which leads to reduced corrosion attack and passivation of the components.
Advantages
Electropolishing not only reduces micro-roughness and increases the gloss for decorative purposes. The surface finish is also associated with greater corrosion resistance, better friction behavior and reduced coating formation.
The working principle of electropolishing means that the surfaces are processed without thermal or mechanical stress. Scratch-free handling is possible.
The low voltages in electropolishing also allow the processing of large workpieces with regular power intervals, right up to entire containers for chemical plant construction.
Disadvantages
Electropolishing involves the use of aggressive acids, which have to be supplemented with other hazardous substances as electrolyte additives, especially for light metals, which is why most companies do not carry out electropolishing themselves, but outsource it to contract manufacturing companies.
The mechanism of action in electropolishing does not work indefinitely. Depending on the material and geometry, there is a limit state that can be achieved from an initial roughness. As a rule, the maximum reduction in roughness is 50% until undesirable effects such as orange peel and milky surfaces occur. This is why electropolishing is very rarely used for additively manufactured stainless steel parts (high initial roughness), for example.
Electropolishing requires clean and grease-free surfaces, so the workpieces typically have to be pre-treated in degreasing baths first. In addition, the acid electrolyte must also be removed from the surface, which, depending on the process chain, can involve rinsing tanks or even cascade rinsing.
Do you want to avoid the disadvantages of electropolishing?
The disadvantages of electropolishing become particularly apparent when the quality requirements for the component surfaces or the flexibility requirements for the production process increase.
Plasma polishing is an innovative technology that has proven itself as an alternative to electropolishing, especially for complex components and high surface requirements. The shorter process times, higher surface quality and the fact that it can also be integrated into in-house production are convincing more and more companies - from classic mechanical engineering to highly sensitive special applications.
Plasma polishing really comes into its own as a replacement for electropolishing stainless steel, copper alloys and titanium. The material removal rate is around 10 times lower than with electropolishing. The noticeable result: smooth and shiny surfaces with significantly higher geometric accuracy. Particularly in the stainless steel sector, high-quality workpieces can be finished without significant edge rounding.
With plasmotion we have developed a portfolio of technologies based on plasma electrolytic processing. The process offers you more shine, more precision and is also more environmentally friendly and safer thanks to the recyclable electrolyte solution. No matter how delicate your components are - we make plasma polishing possible. Our experts use specially adapted electrolyte solutions for your requirements and materials, or develop new ones if required. Our plasma polishing and JETPEP technologies can be integrated into your in-house process chain. Alternatively, we can of course also offer you the treatment of your workpieces on our systems. As the most comprehensive solution provider for plasma electrolytic technologies, we will be happy to advise you!
The alternative: plasma polishing
Plasma polishing is the environmentally friendly alternative to electropolishing.
Clean, smooth, shiny and sterile in a single process step? With its unique operating principle, plasma polishing offers a highly efficient alternative to mechanical or electrochemical polishing. Without any significant thermal or mechanical influences, you can achieve your desired surface finish in around 20 to 200 seconds - even on complex workpieces. Not only can the roughness and appearance of the surface be adapted to your requirements, but tarnishing and discoloration can also be efficiently removed from welds, for example.
Is plasma polishing right for your components? We will be happy to advise you personally.
Minimum roughness
Plasma polishing achieves your target roughness of up to Ra 0.02 µm and largely preserves the initial geometry with minimal edge rounding. However, the desired edge radii can also be set through targeted process control.
Unrivaled brilliance
Our surfaces also impress where aesthetics are required. Plasma polishing offers a higher gloss than electropolishing and enables an even finish on a par with hand polishing.
Improved properties
Improve the feel, corrosion resistance and cleanability of your components with plasma polishing. The plasmotion finish meets even the highest requirements, e.g. in the medical technology and pharmaceutical industries.
Versatile
plasmotion has qualified the process for almost all industrially relevant alloys - from stainless steels to titanium, tool steels, copper, aluminum, brass, CoCr, precious metals, Invar, Nitinol, and many more.
How plasma polishing works
The unique active principle - perfected by plasmotion.
Instead of just electropolishing, we combine electrochemistry and plasma physics in one process.
The workpiece is also processed in an electrolyte bath during plasma polishing. However, special electrolytes from plasmotion based on aqueous salt solutions are used here. At a material-dependent DC voltage in the range of 200 to 400 volts, these evaporate on the surface and form a reactive vapor plasma shell. This flows around the surface and adapts to the corresponding contours. The interplay of electrochemical and plasma-physical processes not only removes burrs and micro-roughness in seconds to a few minutes, it also removes impurities - making degreasing and cleaning pre-treatments a thing of the past.
EFFICIENT
Sustainable
Gentle
Reliable
Applications
Plasma polishing impresses with reliable quality and short cycle times.
Due to its outstanding surface properties, plasma polishing has plasma polishing has quickly proven itself as an alternative to electropolishing, particularly in medical technology and plant engineering. The unique processing approach qualifies it for a wide range of applications. Due to the low material removal, the geometry is retained much better and tolerances are achieved. Even delicate machine components or decorative elements can be reliably polished or deburred.
With our technology, we offer you a extensive service portfolio.
Take your production to the next level with plasma polishing solutions from plasmotion. We develop complete series systems or technology modules that can be used in a wide range of industries - from small part production in the medical sector to large series in the automotive industry.
You can see the strengths of our technologies for yourself by taking a sample first.
With our systems, we also offer you plasmotion's unique technology portfolio as contract manufacturing - reliable and high-quality from batch size 1 to series production. We impress with short delivery times and a wide range of components. This means that we often have suitable solutions for previously impossible applications.
You can see the strengths of our technologies for yourself by taking a sample first.
The magic of plasmotion lies in our electrolytes. Our sustainable salt water-based solutions are 100% harmless according to REACH, environmentally friendly and recyclable. With these, we have shortened process times, optimized processing results and extended service lives. For reliable plasma polishing results in your production, we provide you with the right electrolyte for your application as part of our full-service approach, including collection and preparation.
We support you with our expertise in 3D surface analysis and advise you on the optimum process chain for your desired surface.
Would you like to integrate our technology into your processes instead of electropolishing by external contract manufacturers? We develop customized series systems or individual modules for your company and your requirements to enable plasma polishing directly in your production line. Regardless of whether you manufacture small parts for the medical technology sector or large workpieces for the automotive industry: Our systems impress with modern technology that reliably meets your requirements. We will find a solution for every application. We offer shorter process times thanks to the material-specific electrolytes, while clearly surpassing the results of electropolishing in terms of surface roughness and gloss.
Services from plasmotion
Plasma polishing can be seamlessly integrated into your production.
Replace inefficient and manual processes with plasma polishing - whether in contract manufacturing at plasmotion or with individual systems at your premises. We would be happy to present the advantages of our technologies to you in person - from individual part production to large-scale production. Or see for yourself with a sample of your components!
JETPEP - Jet plasma polishing
Do you have very large parts or area-specific requirements? Then JETPEP is the solution.
For the first time, JETPEP offers the quality and flexibility of manual finishing in a fully automated process. We combine the unique strengths of plasma polishing with the freedom of the electrolyte jet. JETPEP enables the precise cleaning, polishing, deburring and sterilization of your components. JETPEP is the right choice for reliable finishing, especially for surface-specific roughness requirements, complex burr patterns and hard-to-reach contours.
Your next steps
Make your production future-proof - with plasma polishing solutions from plasmotion.
Your challenge - our solution. Your direct route to a customized offer.
Let's talk about your specific concerns.
We would be happy to convince you of the strengths and possibilities of our technologies based on your components. The first step is a sampling. Simply get in touch with us.
Do you have questions about our technologies and applications?
Do your materials and surfaces have special requirements? Are you unsure whether plasma polishing is right for your product? Would you like to know how plasmotion can help you as a solution provider? I will be happy to answer your questions personally.
Your expert for questions
- Sven Friedemann
- Technical sales
- Phone +49 3731 37736 - 31