What is Electrochemical Machining?

Here's a quick introductory video and some additional information about our unique pulsed electrochemical machining (PECM) technology. Feel free to contact us with any questions.

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What is electrochemical machining? Electrochemical machining (ECM) is an advanced non-contact, non-thermal material removal process capable of small features, high quality surfaces, and high repeatability for production parts. Pulsed electrochemical machining (PECM), sometimes called precision electrochemical machining, is a newer, more precise variant of ECM that utilizes a pulsed power supply, but the fundamentals remain the same.

Unlike many other manufacturing processes, such as EDM, no contact exists between the tool and the work piece. Material in the very close proximity of the tool is dissolved by an electrochemical process and the by-products are flushed away with a flowing electrolyte. The resultant part takes on the shape that is an inverse of the tool.

Key Terms in PECM

When discussing PECM there are some key terms that are used on a routine basis:

Term	Definition
Cathode	The cathode functions as the tool in PECM. It may be called the tool, cathode, or electrode. It is typically designed and manufactured for each specific application, and is usually the inverse of the desired shape to be machined.
Anode	Refers to the workpiece or material that will be dissolved. The anode may be wrought stock, a near-net-shape casting, a conventionally machined part, or an additively manufactured component.
Electrolyte	The working fluid flushed between the cathode and anode. This salt-based solution enables electrical current flow and removes by-products such as metal hydroxides created during material dissolution.
Gap (Interelectrode Gap, IEG)	The controlled space maintained between cathode and anode during machining. Gap size strongly influences process performance. PECM enables gaps of roughly 10–100 μm (0.0004–0.004"), allowing much finer feature resolution on the finished part.

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Why use PECM?

Pulsed electrochemical machining possesses some key advantages over other manufacturing processes.

• Hardness is irrelevant - the electrochemical removal process is unaffected by the hardness of the material. The hardness also does not determine the speed of the process. Refer to the materials section for a list of materials that Voxel has experience with, or check out this post for a full description.
  

• Stress free - PECM is a non-contact and non thermal process; therefore, the material properties remain unchanged.
  

• Burr free - the electrochemical process inherently favors sharp corners and is quite often used as a deburring process. Therefore, there is zero risk of burr generation during machining.
  

• Pristine surfaces - Voxel has demonstrated surface finishes of .005-.200 μm Ra (0.2-8 μin Ra) in a variety of materials directly out of the machining process. As a result typical secondary surface finishing techniques can be eliminated.
  

• Near-infinite tool life - The cathode or tool is not consumed during the process of machining. Therefore the same tool can be used for high volume production runs.
  

• Parallel processing - PECM is well-suited for production applications because it can not only form entire surfaces of a part at one time, but also it can also be paralleled to manufacture multiple parts (or multiple features) side-by-side in a single operation.

Case Studies, Applications and More

PECM & Next-Gen Manufacturing

PECM & Surgical Robotics

Superalloys & PECM

If you have more questions, or an idea regarding a part, please get into contact with us. We're looking forward to hearing your ideas!