Adler's Reagent
Adler's Etchant
Material Specific
Composition
Copper ammonium chloride 20–30%, Hydrogen chloride 60–75%, Ferric chloride 10–20%
PACE product, by weight
Method
Swab
Time
5–60 s
Alternative Names
Tags
Reveals
Grain boundaries in ferritic, martensitic, and precipitation-hardening stainless steels; M23C6 carbides; sigma phase; prior austenite grain boundaries in PH stainless after aging
Typical Results
Standard etchant for ferritic, martensitic, and PH stainless steels (410, 416, 17-4 PH, 15-5 PH, 13-8 Mo). Stronger and faster than Kalling's No. 2, especially good for prior-austenite grain boundary reveal in PH stainless H900–H1150 conditions.
Application Method
Method:Swab
Typical Time:5–60 s
Preparation Notes
PACE Adler's Etchant is supplied ready-to-use. Composition (by weight):
| Ingredient | CAS No. | % | Hazardous |
|---|---|---|---|
| Copper ammonium chloride | 10060-13-6 | 20–30% | Yes |
| Hydrogen chloride | 7647-01-0 | 60–75% | Yes |
| Ferric chloride | 7705-08-0 | 10–20% | Yes |
| Water | 7732-18-5 | 2–5% | No |
Application Notes
Swab the freshly polished surface 5–60 s at room temperature. Rinse with water, then ethanol; air-dry.
Troubleshooting
Pitted attack means polishing-induced damage or swab dwelled too long on one spot; repolish lightly with 0.05 µm and re-etch with a moving swab. Under-etch on H900 17-4 PH: extend to 60 s.
Storage Notes
Amber glass at room temperature. Stable several weeks; discard when solution darkens noticeably (Fe(II) → Fe(III) oxidation).
Alternative Etchants
- Kalling's No. 2
- Vilella's Reagent
- Carpenter's
Similar Etchants
- Kalling's No. 2