Model 110 Automatic Twin-Jet Electropolisher Recipes

DANGER. Many of the chemicals used in the solutions below are corrosive, flammable, explosive, and/or toxic — either as stand-alone chemicals or in mixtures. Users are cautioned to review applicable Safety Data Sheets (SDSs) prior to using these chemicals, to strictly follow hazard controls identified in the SDS, and to always use chemicals consistent with manufacturer’s recommendations and applicable regulatory requirements. E.A. Fischione Instruments, Inc. assumes no responsibility for property damage or injury associated with the use of these chemicals or mixtures.

See additional resources, below, to find more electropolisher recipes.

Material

Composition

Solution

Conditions

Comment

Ag

Pure

Sulfuric 6%; Acetic 6%; Methanol 88%; Thiorea Cyanide Solution 12 g

25  C, 10 V, 18 mA

Slightly etched.

Al

Alloy 1100

Perchloric 93%; Sulfuric 6%; Hydrofluoric 1%

-25 °C, 15 V

Must keep below -25 °C.

Al

Alloy 1100

Nitric 10%; Methanol 90%

-10 °C, 10 V, 200 mA

 

Al

Alloy 2024

Nitric 10%; Methanol 90%

-10 °C, 10 V, 200 mA

 

Al

Alloy 5052

Nitric 10%; Methanol 90%

-10 °C, 10 V, 200 mA

 

Al

Alloy 6061

Nitric 10%; Methanol 90%

-10 °C, 10 V, 200 mA

 

Al

Powder

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

8 °C, 30 V, 50 mA

 

Al

Pure

Perchloric 10%; Ethanol 90%

0 °C, 7 V, 80 mA

Excellent result, retains precipitates .

Al

 

Nitric 20 to 25%; Methanol 75 to 80%

 

Add liquid Nitrogen to electrolyte until ice forms. Begin polishing as soon as it reliquefies.

Al Ag

Ag 5 to 25%

Nitric 33%; Methanol 67%

-30 °C, 8 V, 40 mA

 

Al Be

As cast 50%

Nitric 10%; Methanol 90%

-15 °C, 10 V, 200 mA

 

Al Be

As cast 90%

Perchloric 5%; Butoxyethanol 20%; Methanol 75%

8 °C, 35 V

 

Al Be

Be 0.5 to 30%

Perchloric 5%; Butoxyethanol 20%; Methanol 75%

8 °C, 17 V, 100 mA

For higher Be concentrations, use higher voltage.

Al Be Ti

Be 1 to 30%, Ti 1 to 10%

Perchloric 5%; Butoxyethanol 20%; Methanol 75%

8 °C, 20 V, 80 mA

 

Al Be Ti

Be 7%, Ti 2%

Perchloric 5%; Butoxyethanol 20%; Methanol 75%

8 °C, 50 V, 80 mA

 

Al Cu

Cu 4%

Nitric 33%; Methanol 67%

-30 °C, 9 V, 10 mA

Very good result.

Al Cu

Cu 4%

Sulfuric 20%; Methanol 80%

5 °C, 40 V, 50 mA

Excellent result.

Al Cu

 

Nitric 33%; Methanol 67%

-30 to -50 °C

 

Al Cu Ti

Alloy 2000 series

Nitric 25%; Methanol 75%; Hydrofluoric (1-5 drops)

-20 °C

If oxide film is present, remove it by dipping specimen in solution of 16 g Chromic Acid,  35 cc Phosphoric Acid, 65 cc Distilled H20 for 5 to 10 minutes at room temperature.

Al Cu Ti

Alloy 2219

Perchloric 20%; Ethanol 80%

-30 °C, 35 V, 100 mA

Fast electrolyte flow needed. Sample must be removed from holder as quickly as possible and rinsed in three beakers of ethanol to prevent oxide film.

Al Ge

 

Perchloric 10%; Glycerol 20%; Methanol 70%

-10 °C, 18 V, 60 mA

 

Al Li

Li 2 to 3%

Perchloric 5%; Butoxyethanol 20%; Methanol 75%

8 °C, 15 V, 40 mA

 

Al Mg

Mg 3%

Perchloric 10%; Butoxyethanol 20%; Methanol 70%

 

 

Al Mn

Mn 3 to 25%

Perchloric 5%; Butoxyethanol 20%; Methanol 75%

8 °C, 25 V, 125 mA

Very brittle, good polish.

Al Mn S

Mn 33%, S 3%

Perchloric 5%; Butoxyethanol 20%; Methanol 75%

8 °C, 25 V, 125 mA

Very brittle, good polish.

Al Ni

Ni 20 to 80%

Perchloric 5%; Butoxyethanol 20%; Methanol 75%   

5 °C, 37 V, 50 mA

Very good, small change in voltage with composition.

Al Si

Si 0.2%

Nitric 33%; Methanol 67%

-22 °C, 12.5 V, 30 mA

 

Al Si

Si 6%

Nitric 33%; Methanol 67%

-5 °C, 20 V, 200 mA

 

Al Ti

Ti 30 to 50%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

0 °C, 55 V, 40 mA

 

Al Ti

Ti 50%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

0 °C, 25 V, 40 mA

Very good.

Au Fe

Fe 25%

Hydrochloric 6%; Sulfuric 6%; H20 88%

25 °C, 10 V, 60 mA

 

Be

Pure

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

0 °C, 30 V, 40 mA

Slight etch with respect to orientation.

Be Ti

Ti 12%

Sulfuric 20%; Methanol 80%

-10 °C, 25 V, 60 mA

 

Be Ti

Ti 2%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

0 °C, 55 V 40 mA

 

Be V

V 50%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

0 °C, 55 V, 40 mA

 

Bi2Te3

 

Tartaric 2%; Sodium Hydroxide 9%; H2O 89%

 

 

Cd

 

Nitric 33%; Methanol 67%

-30 °C, 7 V, 180  mA

 

Co

Various alloys

Perchloric 20%; Acetic 80%

 

 

Co Fe

Fe 5 to 8%

Perchloric 25%; Acetic 75%

25 °C, 20 V, 80 mA

 

Co Ni

 

Perchloric 25%; Acetic 75%

-30 °C, 25 V

 

Co Ni

 

Perchloric 10%; Acetic 90%

80 V

 

Cu

Pure

Nitric 10%; Methanol 90%

-18 °C, 20 V, 40 mA

 

Cu

Various alloys

Phosphoric 30%; H2O 70%

 

Increase voltage until bubbles form on specimen surface, then reduce voltage until bubbles just disappear.

Cu

 

Nitric 33%; Methanol 67%

-30 to -50 °C

 

Cu Au

Au 50%

Nitric 30%; Methanol 70%

-25 °C, 20 V

 

Cu Be

Be 10%

Nitric 10%; Methanol 90%

-15 °C, 55 V, 80 mA

 

Cu Be

 

Nitric 33%; Methanol 67%

-30 to  -50 °C

 

Cu Be Co

 

Nitric 33%; Methanol 67%

-50 °C, 65 mA

Fast electrolyte flow needed. Rinse in methanol. Surface may oxidize rapidly.

Cu Cr

Cr 3.8%

Nitric 10%; Methanol 90%

0 °C, 35 V, >100 mA

Good result, slight etching at the grain boundaries.

Cu CuO

CuO <5%

Nitric 33%; Methanol 67%

-35 °C, < 8 V, 200 mA

 

Cu Fe

Fe 30%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

-20 °C, 25 V

 

Cu Ni Sn

Single Crystal

Nitric 10%; Methanol 90%

-10 °C, 20 V, 45 mA

 

Cu Ni Sn

Spinodal

Nitric 33%; Methanol 67%

-30 °C, 20 V, 80 mA

 

Cu Pd

Pd 30 to 50%

Perchloric 5%; Butoxyethanol 35%; Methanol 60%

0 °C, 40 V, 200 mA

 

Cu Si

 

Nitric 33%; Methanol 67%   

-50 °C, 65 mA

Fast electrolyte flow needed. Rinse in methanol. Surface may oxidize rapidly.

Cu Ti

Ti 1.6%

Nitric 15%; Methanol 85%

 

 

Cu Ti

 

Nitric 33%; Methanol 67%

-30 to -50° C

 

Discaloy

Gamma

Perchloric 20%; Acetic 80%

25 °C, 5 V, 30 to 45 mA

Use low electrolyte flow.

Discaloy

 

Perchloric 20%; Methanol 80%

-30 °C, 5 V, 30 to 45 mA

Use low electrolyte flow.

Fe

Pure

Perchloric 10%; Acetic 90%

15 °C, 30 V, 30 mA

 

Fe

Various alloys

Perchloric 10%; Acetic 90%

 

 

Fe

 

Chromic 50%; Acetic 50%

27 V

 

Fe AI C

 

Perchloric 5%; Butoxyethanol 35%; Methanol 60%

-20 °C, 15 V

 

Fe AI O

Al <1%; O <1%

Perchloric 10%; Acetic 90%

20 °C, 35 to 40 V, 30 mA

Good result.

Fe Al

 

Nitric 33%; Methanol 67%

-30 to -50 °C

 

Fe Be

Be 25%

Perchloric 5%; Butoxyethanol 35%; Methanol 60%

10 °C, 15 V

 

Fe C

C <1%

Nitric 33%; Methanol 67%

-10 °C, 10 V

 

Fe Cr

Cr 40%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

0 °C, 30 V, 65 mA

 

Fe Cr

Cr 46%

Perchloric 10%; Acetic 90%

0 °C, 30 V

 

Fe Cu

Cu 0.3%

Perchloric 33%; Acetic 33%; Butoxyethanol 34%

10 °C, 20 to 30 V, 200 mA

 

Fe MnS

MnS 2 to 5%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

15 °C, 25 V, 80 mA

Slightly etched.

Fe Ni

Ni 35%

Perchloric 10%; Methanol 90%

 

 

Fe Pd

Pd 15 to 70%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

5 °C, 30 V, 15 mA

 

Fe Si

Si 3%

Nitric 80%; Methanol 20%

35 °C, 20 V, 50 to 60 mA

Large thin areas. Sample must be removed from holder as quickly as possible and rinsed in three beakers of ethanol to prevent oxide film.

Fe Si

Si 3%

Sulfuric 80%; Methanol 20%

-35 °C, 20 V, 50 to 60 mA

Large thin areas. Sample must be removed from holder as quickly as possible and rinsed in three beakers of ethanol to prevent oxide film.

Fe Si O

Si <1%; O <1%

Perchloric 10%; Acetic 90%

20 °C, 35-40 V, 30 mA

Good result.

FV 535

 

Perchloric 20%; Methanol 80%

-20 °C, 30 mA

Use low to moderate electrolyte flow.

Glass

 

Hydrofluoric 90%; Hydrochloric 10%

 

Chemical polish only.

Inconel

Alloy 600

Perchloric 20%; Methanol 80%

-40 °C, 15 to 20 V, 80 to 90 mA

Use low to moderate electrolyte flow.

Inconel

Alloy 690

Perchloric 20%; Methanol 80%

-40 °C, 40 V, 150 mA

Fast electrolyte flow needed.

Inconel

Alloy 706 (cold worked)

Perchloric 20%; Methanol 80%

-40 °C, 150 V, 90 to 100 mA

Fast electrolyte flow needed.

Mar M 509

 

Nitric 4%; Isobutanol 48%; Methanol 48%; Zinc Chloride 40 g

-40 °C, 150 V, 25 to 60 mA

Fast electrolyte flow needed.

Mg

 

Nitric 10%; Methanol 90%

20 V

 

Mo

 

Sulfuric 13%; Methanol 87%

-40 °C, 80 to 100 mA

 

Mo

 

Sulfuric 80%; Hydrofluoric 20%

 

 

Mo C

C <1%

Sulfuric 5%; Glycerol 30%; Methanol 65%

-30 °C, 35 V, 65 mA

 

Mo Hf N

 

Sulfuric 20%; Methanol 80%

25 °C, 17 V, 95 mA

Dip in phosphoric after polishing.

Mo Hf N

 

Perchloric 5%, Butoxyethanol 15%; Methanol 80%

0 °C, 105 V, 90 mA

Slightly etched.

Mo Hf N

 

Sulfuric 20%; Methanol 80%

25 °C, 70 V, >100 mA

Good result, Fast electrolyte flow needed.

Monel

 

Nitric 37%; Methanol 63%

-40 °C, 40 to 50 V, 60 mA

Fast electrolyte flow needed.

Nb

Pure

Hydrofluoric 1%; Sulfuric 6%; Methanol 93%

-40 °C, 40 V, 40 mA

Slightly etched.

Nb

Various alloys

Hydrofluoric 1%; Sulfuric 2%; Methanol 97%

-50 °C

 

Nb

 

Saturated Solution of Ammonium Fluoride in Methanol 13%; Methanol 87%

-30 °C, 150 V

Thins at a rate of 5 µm/min. Maintaining temperature is critical.

Ni

Pure

Perchloric 20%; Acetic 80%

0 °C, 35 V, 50 mA

Excellent result.

Ni Al

Al 50%

Perchloric 3%; Butoxyethanol 32%; Methanol 65%

-45 °C, 18 V, 70 mA

 

Ni Al

 

Perchloric 10%; Methanol 90%

 

 

Ni Cr

Cr 33%

Perchloric 10%; Acetic 90%

10 °C, 55 V, 65 mA

 

Ni Mo

 

Nitric 33%; Methanol 67%

-30 °C to -50 °C

 

Ni Nb

Nb 40%

Perchloric 10%; Ethanol 90%

8 °C, 35 to 40 V

 

Ni V

V 2%

Perchloric 10%; Acetic 90%

10 °C, 55 V, 60 mA

 

Pd

Pure

Perchloric 16%; Acetic 42%; Butoxyethanol 42%

-10 °C, 25 to 30 V

Deforms easily.

Pd Ni

Ni 20 to 50%

Perchloric 16%; Acetic 42%; Butoxyethanol 42%

-10 °C, 25 to 30 V

 

Pt

Pure

Saturated Solution of Calcium Chloride in H2O

25 °C, 35 V

 

Pt C

C <1%

Saturated Solution of Calcium Chloride in H2O

25 °C, 20 V

 

Pt Ga

Ga 4%

Saturated Solution of Calcium Chloride in H2O

25 °C, 20 V

 

Si

 

Hydrofluoric 91%; H2O 9%; Potassium Permanganate 10.5 g

-25 °C

Fast electrolyte flow needed.

Si Cu

Alloy 2124

Nitric 25%; Methanol 75%

-30 °C

 

Stainless Steel

Alloy 302

Perchloric 10%; Ethanol 90%

-25 °C, 25 V, 10 mA

 

Stainless Steel

Alloy 303

Perchloric 5%; Acetic 95%

15 °C, 30 V, 80 mA

 

Stainless Steel

Alloy 304

Perchloric 20%; Acetic 80%

25 °C, 10 to 15 V, 60 to 90 mA

Use low electrolyte flow.

Stainless Steel

Alloy 308

Perchloric 20%; Acetic 80%

25 °C, 10 to 15 V, 60 to 90 mA

Use low electrolyte flow.

Stainless Steel

Alloy 310

Perchloric 5%; Acetic 95%

25 °C, 35 V, 80 mA

 

Stainless Steel

Alloy 420

Sulfuric 40%; Phosphoric 60%

60 °C, 10 V

 

Stainless Steel

Alloy 420

Perchloric 15%; Ethanol 85%

25 °C, 18 V

 

Stainless Steel

 

Sulfuric 40%; Phosphoric 60%

 

 

Steel

Low Carbon

Glacial Acetic 500 mL; Anhydrous Sodium Chromate 100 g

 

 

Ta

Pure

Hydrofluoric 3%; Sulfuric 10%; Methanol 87%

-25 °C, 35 V, 80 mA

Slightly etched.

Ta lr

Ta 50%

Saturated Solution of Calcium Chloride in H2O

25 °C, 20 V, 200 mA

Good result.

Ti

Various alloys

Perchloric 6%; Butoxyethanol 35%; Methanol 59%

-30 °C

 

Ti

 

Perchloric 6%; Butoxyethanol 35%; Methanol 59%

 

 

Ti

 

Sulfuric 3%; Hydrochloric 3%; Methanol 94%

-30 °C

 

Ti Al

 

Perchloric 5%, Butoxyethanol 15%; Methanol 80%

5 °C, 35 V, 30 mA

Slightly etched at grain boundaries

Ti Al

 

Perchloric 20%; Methanol 80%

-30 °C, 55 V, 35 to 45 mA

Fast electrolyte flow needed.

Ti Al

 

Sulfuric 5%; Methanol 95%

-30 °C, 55 V, 35 to 45 mA

Fast electrolyte flow needed.

Ti Al Be

 

Perchloric 5%, Butoxyethanol 15%; Methanol 80%

0 °C, 30 V, 30 mA

 

Ti Al Nb

 

Hydrofluoric 1%; Sulfuric 5%; Methanol 94%

 

 

Ti Al Si

As cast

Sulfuric 20%; Methanol 80%

5 °C, 50 V, 80 mA

Very good result

Ti Al V

Al 6%; V 4%

Perchloric 6%; Butoxyethanol 34%; Methanol 60%

-30 °C, 35 V, 9 mA

Fast electrolyte flow needed.

Ti B

B 7%

Perchloric 20%; Methanol 80%

-20 °C, 11 V, 170 mA

The colder, the better.

Ti Be

Be 12%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

5 °C, 20 V, 40 mA

Good result.

Ti Be

Be 35%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

-10 °C, 15 V, 30 mA

 

Ti C

C 1.5%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

25 °C, 11 V, 150 mA

 

Ti Fe

Fe 25 to 30%

Perchloric 8%; Butoxyethanol 10%; Methanol 70%; H2O 12%

10 °C, 12 V, 120 mA

 

Ti Ge

 

Hydrochloric 3%; Sulfuric 3%; Methanol 94%

-30 °C

 

Ti Mo

Mo 10%

Sulfuric 10%; Methanol 90%

-18 °C, 32 V, 90 mA

 

Ti Nb Mo

 

Sulfuric 10%; Methanol 90%

10 °C, 10 V, 500 mA

 

Ti Ni Fe Si

Fe 1%

Sulfuric 10%; Methanol 90%

-15 °C, 10 V

 

Ti Ni Fe

Ti 50%

Sulfuric 10%; Hydrofluoric 5%; Methanol 85%

20 to 25 V

Slightly etched.

Ti V

V 10%

Sulfuric 10%; Methanol 90%

-18 °C, 33 V, 8 0 mA

 

Ti V Be

Be 10%; V 40%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

-10 °C, 70 to 85 V, 50 mA

 

U

Pure

Sulfuric 20%; Methanol 80%

0 °C, 45 V

 

Udimet

Alloys 710 to 720

Perchloric 20%; Methanol 80%

-20 °C, 45 to 55 V, 55 to 65 mA

Use moderate electrolyte flow.

V Be

Be 50%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

0 °C, 55 V, 40 mA

 

W

 

Sodium Hydroxide 2%; H2O 98%

 

Use low electrolyte flow.

X-45

 

Nitric 4%; Isobutanol 48%; Methanol 48%; Zinc Chloride 40 g

-40 °C, 150 V, 25 to 35 mA

Fast electrolyte flow needed. It takes 12 minutes to thin a 50 µm thick disk.

X-750

 

Perchloric 20%; Methanol 80%

-30 °C, 100 mA

Fast electrolyte flow needed.

Zr

 

Perchloric 20%; Methanol 80%

-40 °C, 35 to 45 mA

Use moderate electrolyte flow.

Zr

 

Perchloric 20%; Acetic 80%

25 °C, 35 to 45 mA

Use moderate electrolyte flow.

Zr

 

Perchloric 20%; Acetic 80%

 

 

Zr Be

Be 5%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

5 °C, 30 V, 60 mA

 

Zr Co Ni

Co 40%; Ni 10%

Perchloric 5%; Butoxyethanol 15%; Methanol 80%

-10 °C, 35 V, 25 mA

 

Zr Nb

Nb 80%

Sulfuric 10%; Methanol 90%

-5 °C, 25 V, 85 mA

Slightly etched.

Zr Nb

Zr 50%; Nb 50%

Sulfuric 10%; Methanol 90%

-10 °C, 22 V, 90 mA

Good result.

 

Additional resources

For additional recipes, refer to:

Petzow, G. Metallographic etching: Techniques for metallotraphy, ceramography, plastography. Materials Park, OH: ASM International, 1999. Print.

Vander, Voort G. F. Metallography, Principles and Practice. Materials Park: ASM International, 1999. Print.