ASTM E407 No. 97ASTM 97
ASTM No. 97
Electrolytic
Composition
187.5g KOH, 245ml H₂O
43%
Method
Electrolytic
Time
10s
Alternative Names
Tags
Reveals
Grain boundaries, phases
Typical Results
Electrolytic etchant for Fe-Cr-Ni alloys. Provides controlled etching for nickel alloys and stainless steels.
Color Effects
Grain boundaries dark
Compatible Materials
Incompatible Materials
Application Method
Method:electrolytic
Typical Time:10 seconds
Voltage:2.5 V
Current Density:0.1 A/cm²
Preparation Notes
CAUTION: KOH is caustic. Dissolve 187.5g potassium hydroxide (KOH) in 245ml distilled water. Use in fume hood with proper PPE.
Application Notes
Use as electrolyte with stainless steel cathode. Apply 2.5V DC, 0.1 A/cm² current density for 5-15 seconds. Sample is anode. Rinse thoroughly with water after etching.
Troubleshooting
CAUTION: Caustic - use proper PPE. Provides controlled etching. Ensure good electrical contact. If no etching, check connections.
Storage Notes
Store in plastic container. Label clearly as caustic. Shelf life: several months.
Alternative Etchants
- 10% Oxalic Acid (Electrolytic)
- Chromic Acid (Electrolytic)
Similar Etchants
- 10% Oxalic Acid (Electrolytic)