0.5% Hydrofluoric AcidHF 0.5%
0.5% HF
Material Specific
Composition
0.5ml HF, 99.5ml H₂O
0.5%
Method
Immersion
Time
5–60 s
Alternative Names
Tags
Reveals
Grain boundaries; second-phase particles (Al2Cu, Mg2Si, MgZn2); constituent particles
Typical Results
Light HF etchant for aluminum and magnesium alloys. Preferred over Keller's on high-Cu wrought alloys (2024, 2219, 7075), where Keller's leaves a Cu-rich stain. Standard for general grain structure in 1xxx through 6xxx series.
Application Method
Method:Immersion
Typical Time:5–60 s
Preparation Notes
CAUTION: HF is extremely hazardous. Mix 0.5ml HF with 99.5ml water in plastic container. Use fume hood and proper PPE.
Application Notes
Immerse in plastic dish 5–60 s at room temperature; swab if attack is uneven. Rinse copiously with cold water, then warm-air dry. Do not alcohol-rinse aluminum.
Troubleshooting
HF burns can be delayed by minutes to hours. Keep calcium gluconate gel on hand and treat any skin contact immediately. Use plastic containers only; HF etches glass.
Storage Notes
PE or PP bottle at room temperature, labeled with HF symbol. Stable indefinitely. Store away from concentrated acids.
Alternative Etchants
- Keller's Reagent
- Barker's Reagent (Electrolytic)
- Al-NaOH Etchant
Similar Etchants
- Keller's Reagent