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Keller's Reagent

Material Specific

Composition

2ml HF, 3ml HCl, 5ml HNO₃, 190ml H₂O

Mixed

Method

Immersion

Time

15s

Alternative Names

Keller's Etchant

Tags

aluminumaluminum-alloymagnesium

Reveals

Grain boundaries, precipitates, phases

Typical Results

Standard etchant for aluminum alloys. Reveals grain structure and second phases.

Color Effects

Grain boundaries dark

Compatible Materials

aluminumaluminum-alloymagnesium

Incompatible Materials

steeltitanium

Application Method

Method:immersion
Typical Time:15 seconds

Preparation Notes

CAUTION: HF is extremely hazardous. Mix 2ml HF, 3ml HCl, 5ml HNO₃, and 190ml water in plastic container.

Application Notes

Immerse sample for 10-20 seconds. Swab if needed. Rinse immediately with copious water.

Troubleshooting

HF causes severe burns. Use in fume hood with proper PPE. Have calcium gluconate gel available.

Storage Notes

Store in plastic container. Label clearly. Extremely hazardous.

Alternative Etchants

  • 0.5% HF
  • Modified Keller's

Similar Etchants

  • 0.5% HF

ASTM References

ASTM E407