Titanium Alloys HF(5%)+HNO₃(30%)

Chemical Etching Formula
TC4(Ti-6Al-4V) with HF(5%)+HNO₃(30%)

This page documents the reference wet chemical etching formula for TC4(Ti-6Al-4V) using the HF(5%)+HNO₃(30%) system. The recipe below covers a sheet-thickness range of 0.01-0.5 mm and is configured for through etch (double-sided). Every value is drawn from operational process records rather than theoretical calculation, and is provided as a starting point for your own process development.

Formula Summary

The table below summarizes every parameter that defines this etching formula. Values listed as ranges scale with sheet thickness across the supported band.

HF(5%)+HNO₃(30%) Etchant System
— °Bé Concentration
1.190 Specific Gravity
35 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.01-0.5 mm Thickness Range
0.07 mm Typical Thickness
0.12-30.76 m/min Conveyor Speed Range
0.99 m/min Typical Speed
8-600 μm Min Hole Ø Range
100-500 μm Min Line Width Range
1-110 μm Undercut Range
2.28 Etch Factor (EF)
95.1% Typical Yield (94.2-95.5%)

Why HF(5%)+HNO₃(30%) for TC4(Ti-6Al-4V)?

For TC4(Ti-6Al-4V), the HF/HNO₃ blend works where chloride chemistries stall: fluoride dissolves the stable oxide, nitric acid re-oxidizes the metal, and the two cycle to give a steady etch. Concentration and temperature control are critical here because the rate is strongly chemistry-dependent.

Process Window & Bath Control

The process window for this HF(5%)+HNO₃(30%) formula centres on 35°C and as specified. Conveyor speed spans 0.12-30.76 m/min over the 0.01-0.5 mm thickness band; the typical operating point is 0.99 m/min. Every 5°C drop in bath temperature requires roughly a 30% reduction in conveyor speed to hold the same etch depth, so temperature stability is the single biggest lever on consistency.

Design Rules & Tolerances

Feature sizes scale with sheet thickness. For this formula the minimum hole diameter ranges 8-600 μm and the minimum line width ranges 100-500 μm across the 0.01-0.5 mm band, following the industry 1.2× (hole) and 1.0× (line) thickness rules. Single-side undercut ranges 1-110 μm, and the etch factor is about 2.28. Size your photomask by subtracting twice the expected undercut from each finished feature dimension.

Design Rule Summary
• Minimum hole diameter range: 8-600 μm
• Minimum line width range: 100-500 μm
• Single-side undercut range: 1-110 μm
• Typical etch factor (EF): 2.28

Yield & Production Economics

This formula delivers a typical yield of 95.1% (range 94.2-95.5%). At that rate, per-part economics are driven mostly by fixed photomask and setup cost for small batches and by sheet utilisation for large runs. The chemistry itself does not change with quantity, so the same recipe serves prototype and production volumes.

Typical Applications

Parts produced with the HF(5%)+HNO₃(30%) formula on TC4(Ti-6Al-4V) are common in medical implants, surgical instruments, aerospace brackets, and corrosion-resistant filters. The burr-free, stress-free nature of chemical etching makes it the preferred process wherever flatness and edge quality matter more than raw throughput.

More Titanium Alloys Formulas

Other formulas in the same material family.

TA1 commercially pure titanium HF(5%)+HNO₃(30%) Through etch (double-sided) TA1 commercially pure titanium HF(5%)+HNO₃(30%) Through etch (double-sided) TA1 commercially pure titanium HF(5%)+HNO₃(30%) Half etch (single-sided) Ta1 Pure Tantalum HF(8%)+HNO₃(30%) Through etch (double-sided) TA2 commercially pure titanium HF(5%)+HNO₃(30%) Through etch (double-sided) TA3 commercially pure titanium HF(5%)+HNO₃(30%) Through etch (double-sided)

Frequently Asked Questions

HF(5%)+HNO₃(30%) balances oxidation rate, bath stability, and photoresist compatibility for TC4(Ti-6Al-4V). More aggressive chemistries over-etch and roughen sidewalls; milder ones stall or attack the resist. This formula's concentration (as specified) and 35°C bath keep the etch factor near 2.28 with predictable undercut.

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WET Etched runs production wet chemical etching lines using the HF(5%)+HNO₃(30%) chemistry. Send us your part drawing and quantity for a full process quote.

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