Titanium AP-16Titanium Etchant AP-16
Ti-AP-16
Material Specific
Composition
Ammonium hydroxide 7–12%, Hydrogen peroxide 0.1–1%, Amorphous silica (colloidal) 30–50%
PACE product, by weight
Method
Chemo-mechanical polish (on wheel)
Time
2–5 min final polish
Alternative Names
Tags
Reveals
Alpha / beta phase contrast on the final-polished surface (no separate etch needed); grain boundaries; transformed beta colonies
Typical Results
Ti-AP-16 is a chemo-mechanical attack-polishing slurry, NOT an etchant. It is used on a polishing wheel as the final prep step. The alkaline NH4OH / H2O2 chemistry chemically attacks titanium while the colloidal silica (30–50%) polishes mechanically. The combined action produces an etch-ready surface with alpha / beta contrast already developed, so no separate Kroll's etch is needed for routine imaging.
Application Method
Method:Chemo-mechanical polish (on wheel)
Typical Time:2–5 min final polish
Preparation Notes
PACE Ti-AP-16 is supplied ready-to-use. Composition (by weight):
| Ingredient | CAS No. | % | Hazardous |
|---|---|---|---|
| Ammonium hydroxide | 1336-21-6 | 7–12% | Yes |
| Hydrogen peroxide | 7722-84-1 | 0.1–1% | Yes |
| Amorphous silica (colloidal) | 7631-86-9 | 30–50% | No |
| Water | 7732-18-5 | 40–60% | No |
Application Notes
Apply to a final-polish pad (microcloth, MicroFloc, or similar). Use as the FINAL step after the standard SiC + diamond progression (typically after 3 µm or 1 µm diamond). Polish 2–5 min at 100–150 RPM with light-to-moderate pressure. Rinse copiously with water during and after; silica residue must be removed completely.
Troubleshooting
Silica residue left on the sample shows up as a uniform "haze" under the microscope; finish with a water-only lap on a clean pad, or rinse longer. Inadequate contrast → polish longer or increase pad pressure. NH4OH evaporates; keep the bottle capped between uses.
Storage Notes
Per PACE SDS, cool storage; the colloidal silica may settle, so agitate before use. Discard if the solid becomes a gel (irreversible silica aggregation).
Alternative Etchants
- Kroll's Reagent (if using a separate-etch workflow on regular polished surface)
- Modified Kroll's Reagent
Similar Etchants
- Colloidal silica attack-polish products (e.g., OP-S, MasterMet 2 for Ti)