Electropolishing Recipes

Material	Composition	Solution	Conditions	Comment
Ag	pure	Sulfuric 6%; Acetic 6%; Methanol 88%; Thiorea Cyanide Solution 12 gms	25C, 10V, 18mA	Slightly etched
Al	Alloy 1100	Perchloric 93%; Sulfuric 6%; Hydrofluoric 1%	-25C, 15V	Must keep below -25C
Al	Alloy 1100	Nitric 10%; Methanol 90%	-10C, 10V, 200mA
Al	Alloy 2024	Nitric 10%; Methanol 90%	-10C, 10V, 200mA
Al	Alloy 5052	Nitric 10%; Methanol 90%	-10C, 10V, 200mA
Al	Alloy 6061	Nitric 10%; Methanol 90%	-10C, 10V, 200mA
Al	powder	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	8C, 30V, 50mA
Al	pure	Perchloric 10%; Ethanol 90%	0C, 7V, 80mA	Excellent result, retains precipitates
Al		Nitric 20-25%; Methanol 75-80%		Add LN2 to electrolyte until ice forms. Begin polishing as soon as it reliquefies.
Al Ag	Ag 5-25%	Nitric 33%; Methanol 67%	-30C, 8V, 40mA
Al Be	As Cast 50%	Nitric 10%; Methanol 90%	-15C, 10V, 200mA
Al Be	As Cast 90%	Perchloric 5%; Butoxyethanol 20%; Methanol 75%	8C, 35V
Al Be	Be 0.5-30%	Perchloric 5%; Butoxyethanol 20%; Methanol 75%	8C, 17V, 100mA	For higher Be concentrations, use higher voltage.
Al Be Ti	Be 1-30%, Ti 1-10%	Perchloric 5%; Butoxyethanol 20%; Methanol 75%	8C, 20V, 80mA
Al Be Ti	Be 7%, Ti 2%	Perchloric 5%; Butoxyethanol 20%; Methanol 75%	8C, 50V, 80mA
Al Cu	Cu 4%	Nitric 33%; Methanol 67%	-30C, 9V, 10mA	Very good result
Al Cu	Cu 4%	Sulfuric 20%; Methanol 80%	5C, 40V, 50mA	Excellent result
Al Cu		Nitric 33%; Methanol 67%	-30C to -50C
Al Cu Ti	Alloy 2000 series	Nitric 25%; Methanol 75%; Hydrofluoric (1-5 drops)	-20C	If oxide film is present, it may be removed by dipping specimen in solution of 16 grams 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%	-30C, 35V, 100mA	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%	-10C, 18V, 60mA
Al Li	Li 2-3%	Perchloric 5%; Butoxyethanol 20%; Methanol 75%	8C, 15V, 40mA
Al Mg	Mg 3%	Perchloric 10%; Butoxyethanol 20%; Methanol 70%
Al Mn	Mn 3-25%	Perchloric 5%; Butoxyethanol 20%; Methanol 75%	8C, 25V, 125mA	Very brittle, good polish
Al Mn S	Mn 33%, S 3%	Perchloric 5%; Butoxyethanol 20%; Methanol 75%	8C, 25V, 125mA	Very brittle, good polish
Al Ni	Ni 20-80%	Perchloric 5%; Butoxyethanol 20%; Methanol 75%	5C, 37V, 50mA	Very good, small change in voltage with composition.
Al Si	Si 0.2%	Nitric 33%; Methanol 67%	-22C, 12.5V, 30mA
Al Si	Si 6%	Nitric 33%; Methanol 67%	-5C, 20V, 200mA
Al Ti	Ti 30-50%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	0C, 55V, 40mA
Al Ti	Ti 50%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	0C, 25V, 40mA	Very good
Au Fe	Fe 25%	Hydrochloric 6%; Sulfuric 6%; H20 88%	25C, 10V, 60mA
Be	pure	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	0C, 30V, 40mA	Slight etch with respect to orientation
Be Ti	Ti 12%	Sulfuric 20%; Methanol 80%	-10C, 25V, 60mA
Be Ti	Ti 2%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	0C, 55V 40mA
Be V	V 50%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	0C, 55V, 40mA
Bi2Te3		Tartaric 2%; Sodium Hydroxide 9%; H2O 89%
Cd		Nitric 33%; Methanol 67%	-30C, 7v, 180 mA
Co	various alloys	Perchloric 20%; Acetic 80%
Co Fe	Fe 5-8%	Perchloric 25%; Acetic 75%	25C, 20V, 80mA
Co Ni		Perchloric 25%; Acetic 75%	-30C, 25V
Co Ni		Perchloric 10%; Acetic 90%	80V
Cu	pure	Nitric 10%; Methanol 90%	-18C, 20V, 40mA
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%	-30C to -50C
Cu Au	Au 50%	Nitric 30%; Methanol 70%	-25C, 20V
Cu Be	Be 10%	Nitric 10%; Methanol 90%	-15C, 55V, 80mA
Cu Be		Nitric 33%; Methanol 67%	-30C to -50C
Cu Be Co		Nitric 33%; Methanol 67%	-50C, 65mA	Fast electrolyte flow needed. Rinse in methanol. Surface may oxidize rapidly.
Cu Cr	Cr 3.8%	Nitric 10%; Methanol 90%	0C, 35V, >100mA	Good result, slight etching at the grain boundaries.
Cu CuO	CuO <5%	Nitric 33%; Methanol 67%	-35C, <8V, 200mA
Cu Fe	Fe 30%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	-20C, 25V
Cu Ni Sn	Single Crystal	Nitric 10%; Methanol 90%	-10C, 20V, 45mA
Cu Ni Sn	Spinodal	Nitric 33%; Methanol 67%	-30C, 20V, 80mA
Cu Pd	Pd 30-50%	Perchloric 5%; Butoxyethanol 35%; Methanol 60%	0C, 40V, 200mA
Cu Si		Nitric 33%; Methanol 67%	-50C, 65mA	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%	-30C to -50C
Discaloy	gamma	Perchloric 20%; Acetic 80%	25C, 5V, 30-45mA	Use low electrolyte flow
Discaloy		Perchloric 20%; Methanol 80%	-30C, 5V, 30-45mA	Use low electrolyte flow
Fe	pure	Perchloric 10%; Acetic 90%	15C, 30V, 30mA
Fe	various alloys	Perchloric 10%; Acetic 90%
Fe		Chromic 50%; Acetic 50%	27V
Fe AI C		Perchloric 5%; Butoxyethanol 35%; Methanol 60%	-20C, 15V
Fe AI O	Al <1%; O <1%	Perchloric 10%; Acetic 90%	20C, 35-40V, 30mA	Good result
Fe Al		Nitric 33%; Methanol 67%	-30C to -50C
Fe Be	Be 25%	Perchloric 5%; Butoxyethanol 35%; Methanol 60%	10C, 15V
Fe C	C <1%	Nitric 33%; Methanol 67%	-10C, 10V
Fe Cr	Cr 40%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	0C, 30V, 65mA
Fe Cr	Cr 46%	Perchloric 10%; Acetic 90%	0C, 30V
Fe Cu	Cu 0.3%	Perchloric 33%; Acetic 33%; Butoxyethanol 34%
Fe MnS	MnS 2-5%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	10C, 20-30V, 200mA
Fe Ni	Ni 35%	Perchloric 10%; Methanol 90%	15C, 25V, 80mA	Slightly etched
Fe Pd	Pd 15-70%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	5C, 30V, 15mA
Fe Si	Si 3%	Nitric 80%; Methanol 20%	-35C, 20V, 50-60mA	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%	-35C, 20V, 50-60mA	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%	20C, 35-40V, 30mA	Good result
FV 535		Perchloric 20%; Methanol 80%	-20C, 30mA	Use low to moderate electrolyte flow
Glass		Hydrofluoric 90%; Hydrochloric 10%		Chemical Polish Only
Inconel	Alloy 600	Perchloric 20%; Methanol 80%	-40C, 15-20V, 80-90mA	Use low to moderate electrolyte flow
Inconel	Alloy 690	Perchloric 20%; Methanol 80%	-40C, 40V, 150mA	Fast electrolyte flow needed
Inconel	Alloy 706 (cold worked)	Perchloric 20%; Methanol 80%	-40C, 150V, 90-100mA	Fast electrolyte flow needed
Mar M 509		Nitric 4%; Isobutanol 48%; Methanol 48%; Zinc Chloride 40 gms	-40C, 150V, 25-60mA	Fast electrolyte flow needed
Mg		Nitric 10%; Methanol 90%	20V
Mo		Sulfuric 13%; Methanol 87%	-40C, 80-100mA
Mo		Sulfuric 80%; Hydrofluoric 20%
Mo C	C <1%	Sulfuric 5%; Glycerol 30%; Methanol 65%	-30C, 35V, 65mA
Mo Hf N		Sulfuric 20%; Methanol 80%	25C, 17V, 95mA	Dip in phosphoric after polishing
Mo Hf N		Perchloric 5%, Butoxyethanol 15%; Methanol 80%	0C, 105V, 90mA	Slightly etched
Mo Hf N		Sulfuric 20%; Methanol 80%	25C, 70V, >100 mA	Good result, Fast electrolyte flow needed
Monel		Nitric 37%; Methanol 63%	-40C, 40-50V, 60mA	Fast electrolyte flow needed
Nb	pure	Hydrofluoric 1%; Sulfuric 6%; Methanol 93%	-40C, 40V, 40mA	Slightly etched
Nb	various alloys	Hydrofluoric 1%; Sulfuric 2%; Methanol 97%	-50C
Nb		Saturated Solution of Ammonium Fluoride in Methanol 13%; Methanol 87%	-30C, 150V	Thins at a rate of 5 microns/minute. Maintaining temperature is critical.
Ni	pure	Perchloric 20%; Acetic 80%
Ni Al	Al 50%	Perchloric 3%; Butoxyethanol 32%; Methanol 65%	0C, 35V, 50mA	Excellent result
Ni Al		Perchloric 10%; Methanol 90%	-45C, 18V, 70mA
Ni Cr	Cr 33%	Perchloric 10%; Acetic 90%	10C, 55V, 65mA
Ni Mo		Nitric 33%; Methanol 67%	-30C to -50C
Ni Nb	Nb 40%	Perchloric 10%; Ethanol 90%	8C, 35-40V
Ni V	V 2%	Perchloric 10%; Acetic 90%	10C, 55V, 60mA
Pd	pure	Perchloric 16%; Acetic 42%; Butoxyethanol 42%	-10C, 25-30V	Deforms easily
Pd Ni	Ni 20-50%	Perchloric 16%; Acetic 42%; Butoxyethanol 42%	-10C, 25-30V
Pt	pure	Saturated Solution of Calcium Chloride in H20	25C, 35V
Pt C	C <1%	Saturated Solution of Calcium Chloride in H20	25C, 20V
Pt Ga	Ga 4%	Saturated Solution of Calcium Chloride in H20	25C, 20V
Si		Hydrofluoric 91%; H20 9%; Potassium Permanganate 10.5 gms	-25C	Fast electrolyte flow needed
Si Cu	Alloy 2124	Nitric 25%; Methanol 75%	-30C
Stainless Steel	Alloy 302	Perchloric 10%; Ethanol 90%	-25C, 25V, 10 mA
Stainless Steel	Alloy 303	Perchloric 5%; Acetic 95%	15C, 30V, 80mA
Stainless Steel	Alloy 304	Perchloric 20%; Acetic 80%	25C, 10-15V, 60-90mA	Use low electrolyte flow
Stainless Steel	Alloy 308	Perchloric 20%; Acetic 80%	25C, 10-15V, 60-90mA	Use low electrolyte flow
Stainless Steel	Alloy 310	Perchloric 5%; Acetic 95%	25C, 35V, 80mA
Stainless Steel	Alloy 420	Sulfuric 40%; Phosphoric 60%	60C, 10V
Stainless Steel	Alloy 420	Perchloric 15%; Ethanol 85%	25C, 18V
Stainless Steel		Sulfuric 40%; Phosphoric 60%
Steel	Low Carbon	Glacial Acetic 500 ml; Anhydrous Sodium Chromate 100 gms
Ta	pure	Hydrofluoric 3%; Sulfuric 10%; Methanol 87%	-25C, 35V, 80mA	Slightly etched
Ta lr	Ta 50%	Saturated Solution of Calcium Chloride in H20	25C, 20V, 200mA	Good result
Ti	various alloys	Perchloric 6%; Butoxyethanol 35%; Methanol 59%	-30C
Ti		Perchloric 6%; Butoxyethanol 35%; Methanol 59%
Ti		Sulfuric 3%; Hydrochloric 3%; Methanol 94%	-30C
Ti Al		Perchloric 5%, Butoxyethanol 15%; Methanol 80%	5C, 35V, 30mA	Slightly etched at grain boundaries
Ti Al		Perchloric 20%; Methanol 80%	-30C, 55V, 35-45mA	Fast electrolyte flow needed
Ti Al		Sulfuric 5%; Methanol 95%	-30C, 55V, 35-45mA	Fast electrolyte flow needed
Ti Al Be		Perchloric 5%, Butoxyethanol 15%; Methanol 80%	0C, 30V, 30mA
Ti Al Nb		Hydrofluoric 1%; Sulfuric 5%; Methanol 94%
Ti Al Si	as cast	Sulfuric 20%; Methanol 80%	5C, 50V, 80mA	Very good result
Ti Al V	Al 6%; V4%	Perchloric 6%; Butoxyethanol 34%; Methanol 60%	-30C, 35V, 9mA	Fast electrolyte flow needed
Ti B	B 7%	Perchloric 20%; Methanol 80%	-20C, 11V, 170mA	The colder, the better
Ti Be	Be 12%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	5C, 20V, 40mA	Good result
Ti Be	Be 35%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	-10C, 15V, 30mA
Ti C	C 1.5%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	25C, 11V, 150mA
Ti Fe	Fe 25-30%	Perchloric 8%; Butoxyethanol 10%; Methanol 70%; H20 12%	10C, 12V, 120mA
Ti Ge		Hydrochloric 3%; Sulfuric 3%; Methanol 94%	-30C
Ti Mo	Mo 10%	Sulfuric 10%; Methanol 90%	-18C, 32V, 90mA
Ti Nb Mo Si		Sulfuric 10%; Methanol 90%	10C, 10V, 500mA
Ti Ni Fe	Fe 1%	Sulfuric 10%; Methanol 90%	-15C, 10V
Ti Ni Fe	Ti 50%	Sulfuric 10%; Hydrofluoric 5%; Methanol 85%	20-25V	Slightly etched
Ti V	V 10%	Sulfuric 10%; Methanol 90%	-18C, 33V, 80mA
Ti V Be	Be 10%; V 40%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	-10C, 70-85V, 50mA
U	pure	Sulfuric 20%; Methanol 80%	0C, 45V
Udimet	Alloys 710-720	Perchloric 20%; Methanol 80%	-20C, 45-55V, 55-65mA	Use moderate electrolyte flow
V Be	Be 50%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	0C, 55V, 40mA
W		Sodium Hydroxide 2%; H2O 98%		Use low electrolyte flow
X-45		Nitric 4%; Isobutanol 48%; Methanol 48%; Zinc Chloride 40 gms	-40C, 150V, 25-35mA	Fast electrolyte flow needed. It takes 12 minutes to thin a 50 micron thick disk.
X-750		Perchloric 20%; Methanol 80%	-30C, 100mA	Fast electrolyte flow needed
Zr		Perchloric 20%; Methanol 80%	-40C, 35-45mA	Use moderate electrolyte flow
Zr		Perchloric 20%; Acetic 80%	25C, 35-45mA	Use moderate electrolyte flow
Zr		Perchloric 20%; Acetic 80%
Zr Be	Be 5%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	5C, 30V, 60mA
Zr Co Ni	Co 40%; Ni 10%	Perchloric 5%; Butoxyethanol 15%; Methanol 80%	-10C, 35V, 25mA
Zr Nb	Nb 80%	Sulfuric 10%; Methanol 90%	-5C, 25V, 85mA	Slightly etched
Zr Nb	Zr 50%; Nb 50%	Sulfuric 10%; Methanol 90%	-10C, 22V, 90mA	Good result

CAUTION: Perchloric acid can be very explosive. Only use electrolytes containing perchloric acid in a safety fume hood capable of handling perchlorics.

Selected recipes courtesy of Mark Wall - Lawrence Livermore National Laboratory, James Haugh - Westinghouse Electric Company & Mary Grace Burke - Bechtel Bettis, Inc.

For additional recipes, refer to Practical Methods in Electron Microscopy, Volume 11, Thin Foil Preparation for Electron Microscopy by Peter J. Goodhew, Elsevier Science Publishers B.V., 1985 and Transmission Electron Microscopy of Materials by Gareth Thomas and Michael J. Goringe, John Wiley & Sons, Inc., 1979