Selective Electroplating

Selective Electroplating also known as Brush Electroplating, Selective Electroplating or Electro Chemical Metalizing is a metal/alloy deposition method for localised electroplating without using an immersion tank system. (See http://en.wikipedia.org/wiki/Electroplating)

The process utilises an electrical current to plate a desired material from a solution and bond a conductive object with a thin layer of material such as a metal or an alloy. Surfaces liable to be plated may vary from cm² to m². The deposit thickness ranges from a few microns to several tenths of a millimetre. (See Marlinec – Selective Electroplating)

 

Why use Selective Electroplating?

Selective Electroplating is primarily used for depositing a layer to bestow a desired property/characteristic to a surface that otherwise lacks that property.

 

Unique features of Selective Electroplating

It is fast
 +Can deposit hard metals (Rockwell C50 and above) at 25µm/minute
 +Can deposit soft metals at up to 250µm/minute
It is ideal for dimensional restoration
It is portable which makes it ideal for field repairs or on assemblies
It has excellent bond strength exceeding 97MPa (>14 000 PSI)
A wide variety of metals, alloys and conversion coatings can be applied with the same equipment

 

Benefits

Selective areas can be plated. No need for a tank system
Excellent adhesion. Comply with numerous specifications throughout various industries
No thermal distortion of any kind
Wear and abrasion resistance
Excellent thickness control
Portability
Fast turnaround time
Dimensional restoration of original equipment manufacturer’s dimensions
Practically no dimensional restriction to component size that can be plated
Good corrosion resistance
Good lubricity
Exceptional hardness
Defect repairs
Anti-galling properties
Aesthetic qualities

 

Selective Electroplating vs Other Repair Methods  

  

Criteria

Selective Electroplating

Welding

Metallizing

Electroplating

Precise Build-up Capability

Excellent

Poor

Poor

Fair to Good

Bond Quality

Excellent

Excellent

Fair to Good

Good

Thermal Distortion or Internal Stresses

None

Frequently

Sometimes

None

Density of Deposit (Porosity)

Very Dense*

Very dense but with blow holes

70-90% theoretical density

Dense

Portable

Yes

Yes

Sometimes

No

Need for Post Repair Machining or Grinding

Not required on deposits up to 0.025mm. on smooth surface

 

Always required

Most always required

Usually required

Hydorgen Embritement

No*

No

No

No

* Deposits are approximately 25% and 790% less porous than electroplated and metallized coatings respectively.


Plating Material Surface Hardness

 

Plating Deposit Rockwell HardnessApplication
Cobalt Machinable 40RcHeavy metal build-up particulary in the repair of over machined parts.
Copper (heavy build alkaline) 24RcHeavy metal build-up particulary in the repair of over machined parts.
Nickel Acid High Build 55RcBuild-up of over machined parts subject to wear and/or heat.
Nickel High Speed 52RcBuild-up and resizing, worn or over machined parts.
Nickel Tungsten 68RcHard wear resistant finish over other deposits.
Nickel Cobalt 44-48RcBuild-up and resizing of part subject to wear and above normal heat.
Cadmium 40RcUsed for corrosion protection of aircraft parts on ultra-high strength steel.