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Cascade e-Ion Plasma™ Surface Smoothing & Deburring

Obtain Ra down to 0.3-1-5 um within minutes without the use of harsh chemicals. Treatment time with Ionic Deburring varies depending on the starting roughness, but is generally within a minute for most surfaces.

Surface Roughness and Peening

  • Surface roughness is a measure of the texture of a surface. 
  • Commonly reported as Ra number (the absolute arithmetic average roughness of a surface).
  • Or reported with a Rq number (root mean squared RMS value of roughness).    
  • More advanced reporting procedure include values for waviness and surface skewness; however Ra and Rq capture the roughness property adequately.
  • Units:  The engineering units for both Ra and Rq are either microinch (u-inch) or micrometers (um).
  • 1 micron (um) = 39.37 u-inch
  • Peening or burring is the process of working a metal-surface to improve its material properties.  Ion Peening with the e-Ion Plasma is a relatively new processes that can be used for curved and complex shapes.
  • Cast surfaces display Ra of about 50-250 u-inch.  Sand castings display the higher roughness, plaster shell type investment castings and die castings show the lower values of roughness.  Squeeze castings also display a higher average roughness.

Participate in no-burr technology with the case e-ion or with the use of GoldenBlue® tools


  • Surface roughness can impact the look-and-feel of products.  A bad roughness can effect the durability, fatique, bio-compatibility and reliability of the processed part.  Cascade e-ion information request.
  • Several quick machining operations leave behind burrs.
  • Roughness impacts life by impacting wear resistance, erosion resistance, fatigue resistance, creep-fatigues interaction and other material design parameters.
  • Roughness is called out for metallic, composite and ceramic parts used in turbo machinery, combustors, engines, cylinders and other engineering parts.
  • For polymeric and other soft surfaces the more commonly reported measurement number is related to specular reflectivity, the Ra and Rq are generally not called-out.
  • A bad casting finish can dramatically alter the energy efficiency in any fluid flow device e.g. a pump or turbocharger.  High roughness can cause turbulence. Roughness can be controlled with e-Ion techniques. Make casting surface harder or nitride complex surfaces.
  • For more information regarding surface roughness and surface finishing, see this site which discusses how coatings fill the voids between sand grains and can also act as a refractory, limiting the defects and loss of integrity that can occur with higher melting point alloys. Make casting surfaces harder and smoother.


Role of the Cascade e-Ion Plasma Plume

The Cascade e-ion Plasma is a versatile machine that may be used to reduce the surface roughness for metals (Cascade e-Ion source), ceramics (Cascade e-Ion EIZ) or soft plastics (e-Ion LIP).  With the e-Ion Plasma machine one may rapidly deburr down to Rq numbers in the order of about 1 um, depending on the ions used and other properly set conditions that change for specific alloy surfaces.  Known information on the required conditions may be obtained by contacting the manufacturer, MHI.  Sand Castings with Ra =50 um can be reduced to Ra or the order of 1 um.  Under certain conditions nanometer roughness values may be attempted.


In its several modes the e-Ion Plasma™ can deburr, ionic co-deposit to fill surface porosity and be used simultaneously for thermal action in different modes to obtain the best surface.  Numerous studies are underway for smoothening glasses, semiconductors and high hardness materials such as carbides, nitrides and borides.  Selective smoothening studies with composites and muticompositional alloys are underway also.



Every competitive deburring process has advantages and disadvantages. When comparing processes the comparison should include speed, reliability, possible to start with high roughness for any process, energy efficiency, chemicals and other environmental foot-print including noise for comparison making.  Mechanical processing (such as drilling, grinding, stone-tumbling and polishing) may change or damage materials on account of focused stresses which then may lead to residual cracks, residual tensile stresses and/or changes in the microstructure; thus reducing the service life of the part.  Electro-polishing may require chemicals that need to be stored, replenished and disposed.  The e-ion on the other hand uses only air (or other gas of choice) and electricity as input to the machine.  High kinetic and thermal energy ions are used for deburring in the e-Ion Plasma process.  It is a noiseless and controllable process and because of the small foot print may be used on a table-top for almost all configurations.  No water cooling or water/contaminant emissions.   Cascade e-Ion Plasma™ can be used for Plasma Peening.  Continuous product with a belt or robot part-handler is easily possible.  MHI provides all the high temperature holding accessories required by the user for addition to a standard part manipulators.  See also welding page.


Additional Benefits with the Cascade e-Ion

Although not all the benefits of a new technology like the e-Ion Plasma can be known at this point, several may be anticipated.  For example, with the e-Ion Plasma, the rapid deburring step can be combined with a rapid surface niriding and bulk sintering step.  The ions do not require line-of-sight beam and the product does not have to be electrically grounded.   This type of sintering is called 4DSintering® which is a Trademark of MHI Inc.  Simultaneous ion peening operations can be envisaged. Similarly welding and weld smoothing may be anticipated as simultaneously feasible.  Welding scale and the chromium depleted layer underneath weld roughness must be removed for example for Stainless Steel sea-side corrosion resistance.   Mechanical polishing to match the finish on the parent material is often used but this must be done carefully so that cracks are not introduced which can lead to stress-corrosion cracking.   More Online Information.   Sometimes surface roughness is further reduced by deposition.  The e-Ion depositor attachment may be used with the same machine.


ExampleStarting from surface with a Ra = 20-40um, for an unsintered powder metallurgy produced alloy part for an alloy that sinters around 1700K, a Ra = 4um surface is easily obtained in minutes to an hour of non-line-of-sight surface e-Ion deburring operation. Multiple parts can be made simultaneously. The production cost saving per part when comparing labor time for 1 hour vs. 3 days is substantial.  The savings from lessened environment degradation is substantial.  The energy savings per year could be thousands of dollars in benefit.  Please contact MHI for more precise calculations and to work with you to ensure best amortization cost for your specific location.  Please Contact Us for more information for the best surface finish for metals, ceramics, glass, oxides, garnets, silicon carbide and many other materials that require nanoscale smoothening. 



Grit   to    Microns































Note also that 1 micron (um) = 39.37 u-inch

Chart of Grid to Microns

Cascade e-Ion

A high energy and high velocity e-Ion Plasma™ CleanElectricFlame is shown below which can be used with the deburring holder for in-situ

deburring or ion-peening operation within minutes for the completed casting (entire surface), forging or powder-metallurgy fabricated parts.  Curved and non-line-of-sight regions can be treated. 


Easy method to deburr steel tool steel and die steel

Deburr steel parts in a few seconds.  Simultaneously nitride or oxynitride as required.  

On the left is nitrided and deburred.  On the right is the surface before duburring.

Typical Size/Footprint:   A typical ~ 14 kW Cascade e-Ion Plasma™ configuration fits on half a standard desk-top table.  Plug and Play type installation.

Expected operating cost is a few cents per part but please Contact Us for your specific application.



Biomedical screw


Microstructure Titanium Alloy Plasma Nitrided with Cascade e-Ion GoldenBlue(TM)Extremely low roughness Cascade e-ion Plasma Treatment of Titanium Alloys

Pictures above are hip/spine inserts and screws common shapes with magnification of 50,000X and 100,000X to indicate surface finish possibilities.

Easily nitride Ti-Al-V (Ti64) with the Cascade e-Ion Plasma Plume

The Cascade e-Ion is used for Titanium Alloys (including multilayer graded peening), Co-Cr-Mo type biomedical alloys,

Stainless Steel, High density plastics, dental alloys, gold alloys, superalloys, Nitinol oxide conditioning, Ni-Ti, Ti-Al, Ni-Al, castings, forgings and many others where roughness needs to be reduced or surfaces have to be peened.

Please Contact Us for your specific application

MHI offers complex part manipulators from robotic arms to continuous belts

Before and after pictures of Deburr Copper Zinc Nitride after GoldenBlue and deburr

Before e-Ion Ra= 20um » After treatment Ra= 4um surface shown above.  No burrs.

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750 Redna Terrace Cincinnati, OH 45215, USA
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