Barker's Reagent (Electrolytic)

Electrolytic

Composition

Fluoboric Acid (HBF₄)

Concentrated

Method

Electrolytic

Time

60s

Alternative Names

Reveals

Grain boundaries, interference colors

Typical Results

Electrolytic etchant for aluminum. Produces excellent grain boundary contrast and interference colors. Very effective for aluminum microstructures.

Color Effects

Grain boundaries dark, interference colors visible

Compatible Materials

Incompatible Materials

Application Method

Method:electrolytic

Typical Time:60 seconds

Voltage:20 V

Current Density:0.1 A/cm²

Preparation Notes

CAUTION: Fluoboric acid is corrosive. Use concentrated fluoboric acid (HBF₄) as electrolyte. Use in fume hood with proper PPE.

Application Notes

Use as electrolyte with aluminum or stainless steel cathode. Apply 15-30V DC, 0.1 A/cm² current density for 30-90 seconds. Sample is anode. Rinse thoroughly with water after etching.

Troubleshooting

Produces excellent interference colors for phase identification. Ensure good electrical contact. If no etching, check connections and increase voltage slightly.

Storage Notes

Store in plastic container. Label clearly as corrosive. Shelf life: several months.