Electrochemical machining (ECM) is a precise method for removing metal through an electrochemical process, ideal for mass production and machining hard materials like titanium aluminides and Inconel. It works only on electrically conductive metals, cutting complex shapes with no tool wear or thermal damage. In ECM, a cathode tool removes material from a positively charged anode workpiece using a pressurized electrolyte, dissolving metal which is then flushed away. Developed commercially in 1959 and comparable to but distinct from EDM, ECM excels in producing parts like turbine blades and performing effective deburring, offering improved surface finishes without sparks or mechanical stress.
Advantages
- Complex concave curvature components can be produced easily by using concave tools.
- Tool wear is zero, same tool can be used for producing infinite number of components. 11
- High surface quality may be achieved.
- No direct contact between tool and work material so there are no forces and residual stresses. 12
- The surface finish produced is excellent.
- Less heat is generated.
Disadvantages
- The saline (or acidic) electrolyte poses the risk of corrosion to tool, workpiece and equipment.13
- Only electrically conductive materials can be machined.
- High Specific Energy consumption. 14
- It cannot be used for soft materials.
Currents involved
The needed current is proportional to the desired rate of material removal, and the removal rate in mm/minute is proportional to the amps per square mm.
Typical currents range from 0.1 amp per square mm to 5 amps per square mm. Thus, for a small plunge cut of a 1 by 1 mm tool with a slow cut, only 0.1 amps would be needed.
However, for a higher feed rate over a larger area, more current would be used, just like any machining process—removing more material faster takes more power.
Thus, if a current density of 4 amps per square millimeter was desired over a 100×100 mm area, it would take 40,000 amps (and much coolant/electrolyte).
Setup and equipment
ECM machines come in both vertical and horizontal types. Depending on the work requirements, these machines are built in many different sizes as well. The vertical machine consists of a base, column, table, and spindle head. The spindle head has a servo-mechanism that automatically advances the tool and controls the gap between the cathode (tool) and the workpiece.15
CNC machines of up to six axes are available.16
Copper is often used as the electrode material. Brass, graphite, and copper-tungsten are also often used because they are easily machined, they are conductive materials, and they will not corrode.17
Applications
- Die sinking
- Drilling jet engine turbine blades
- Multiple hole drilling
- Machining steam turbine blades
- Micromachining
- Profiling and contouring
- Rifling
Similarities between EDM and ECM
- No contact occurs between tool and workpiece: a small gap separates them.
- The tool and workpiece must both be conductors of electricity.
- A fluid is used as a medium between the tool and the work piece (conductive for ECM and dielectric for EDM).
- The tool is fed continuously towards the workpiece to maintain a constant gap between them (ECM may incorporate intermittent or cyclic, typically partial, tool withdrawal).
Difference between ECM and ECG
- Electrochemical grinding (ECG) is similar to electrochemical machining (ECM) but uses a contoured conductive grinding wheel instead of a tool shaped like the contour of the workpiece.
See also
External links
References
Todd, H. Robert; Allen, K. Dell; Alting, Leo (1994), Manufacturing Processes Reference Guide (1st ed.), Industrial Press Inc., pp. 198–199, ISBN 0-8311-3049-0. /wiki/ISBN_(identifier) ↩
Valenti, Michael, "Making the Cut." Mechanical Engineering, American Society of Mechanical Engineers, 2001. http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html Archived 2010-07-05 at the Wayback Machine accessed 2/23/2010 http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html ↩
Todd, H. Robert; Allen, K. Dell; Alting, Leo (1994), Manufacturing Processes Reference Guide (1st ed.), Industrial Press Inc., pp. 198–199, ISBN 0-8311-3049-0. /wiki/ISBN_(identifier) ↩
Valenti, Michael, "Making the Cut." Mechanical Engineering, American Society of Mechanical Engineers, 2001. http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html Archived 2010-07-05 at the Wayback Machine accessed 2/23/2010 http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html ↩
Valenti, Michael, "Making the Cut." Mechanical Engineering, American Society of Mechanical Engineers, 2001. http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html Archived 2010-07-05 at the Wayback Machine accessed 2/23/2010 http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html ↩
Todd, H. Robert; Allen, K. Dell; Alting, Leo (1994), Manufacturing Processes Reference Guide (1st ed.), Industrial Press Inc., pp. 198–199, ISBN 0-8311-3049-0. /wiki/ISBN_(identifier) ↩
"Process History - ECM Technologies". http://electrochemicalmachining.com/technology/process-history ↩
Valenti, Michael, "Making the Cut." Mechanical Engineering, American Society of Mechanical Engineers, 2001. http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html Archived 2010-07-05 at the Wayback Machine accessed 2/23/2010 http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html ↩
Valenti, Michael, "Making the Cut." Mechanical Engineering, American Society of Mechanical Engineers, 2001. http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html Archived 2010-07-05 at the Wayback Machine accessed 2/23/2010 http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html ↩
Todd, H. Robert; Allen, K. Dell; Alting, Leo (1994), Manufacturing Processes Reference Guide (1st ed.), Industrial Press Inc., pp. 198–199, ISBN 0-8311-3049-0. /wiki/ISBN_(identifier) ↩
"Electrochemical machining [SubsTech]". www.substech.com. Retrieved 2024-01-17. https://www.substech.com/dokuwiki/doku.php?id=electrochemical_machining ↩
"Electrochemical machining [SubsTech]". www.substech.com. Retrieved 2024-01-17. https://www.substech.com/dokuwiki/doku.php?id=electrochemical_machining ↩
Valenti, Michael, "Making the Cut." Mechanical Engineering, American Society of Mechanical Engineers, 2001. http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html Archived 2010-07-05 at the Wayback Machine accessed 2/23/2010 http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html ↩
"Electrochemical machining [SubsTech]". www.substech.com. Retrieved 2024-01-17. https://www.substech.com/dokuwiki/doku.php?id=electrochemical_machining ↩
Todd, H. Robert; Allen, K. Dell; Alting, Leo (1994), Manufacturing Processes Reference Guide (1st ed.), Industrial Press Inc., pp. 198–199, ISBN 0-8311-3049-0. /wiki/ISBN_(identifier) ↩
Valenti, Michael, "Making the Cut." Mechanical Engineering, American Society of Mechanical Engineers, 2001. http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html Archived 2010-07-05 at the Wayback Machine accessed 2/23/2010 http://www.memagazine.org/backissues/membersonly/nov01/features/makcut/makcut.html ↩
Todd, H. Robert; Allen, K. Dell; Alting, Leo (1994), Manufacturing Processes Reference Guide (1st ed.), Industrial Press Inc., pp. 198–199, ISBN 0-8311-3049-0. /wiki/ISBN_(identifier) ↩