Titanium Alloys HF(5%)+HNO₃(30%)

Chemical Etching Formula
TC6 Titanium Alloy with HF(5%)+HNO₃(30%)

This page documents the reference wet chemical etching formula for TC6 Titanium Alloy using the HF(5%)+HNO₃(30%) system. The recipe below covers a sheet-thickness range of 0.05-0.5 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
1.200 Specific Gravity
36 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.05-0.5 mm Thickness Range
0.18 mm Typical Thickness
0.12-1.36 m/min Conveyor Speed Range
0.17 m/min Typical Speed
60-600 μm Min Hole Ø Range
100-500 μm Min Line Width Range
11-111 μm Undercut Range
2.25 Etch Factor (EF)
95.1% Typical Yield (94.2-95.4%)

Why HF(5%)+HNO₃(30%) for TC6 Titanium Alloy?

Hydrofluoric/nitric formulas are used for refractory and titanium-family metals such as TC6 Titanium Alloy because the fluoride ion is one of the few species that will break down their tenacious passive oxide. The nitric component oxidizes the freshly exposed metal so the fluoride can keep working. Handling demands are high, but for TC6 Titanium Alloy there is rarely a practical alternative.

Process Window & Bath Control

The process window for this HF(5%)+HNO₃(30%) formula centres on 36°C and as specified. Conveyor speed spans 0.12-1.36 m/min over the 0.05-0.5 mm thickness band; the typical operating point is 0.17 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

When laying out artwork for TC6 Titanium Alloy at through etch (double-sided), plan for a minimum hole diameter in the 60-600 μm range and a minimum line width in the 100-500 μm range, depending on the chosen sheet thickness within 0.05-0.5 mm. The etch factor of ~2.25 and undercut range of 11-111 μm determine how much the mask must be biased to land the finished dimension on target.

Design Rule Summary
• Minimum hole diameter range: 60-600 μm
• Minimum line width range: 100-500 μm
• Single-side undercut range: 11-111 μm
• Typical etch factor (EF): 2.25

Yield & Production Economics

This formula delivers a typical yield of 95.1% (range 94.2-95.4%). 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

TC6 Titanium Alloy etched with this recipe typically ends up in medical implants, surgical instruments, aerospace brackets, and corrosion-resistant filters. Because chemical etching applies no mechanical or thermal load, the finished features are free of work-hardening and heat-affected zones — a decisive advantage over stamping or laser cutting for these uses.

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

Target specific gravity is 1.200 for this formula. Check it each shift with a calibrated hydrometer. A falling SG indicates the bath is becoming depleted; a rising SG usually points to evaporative water loss that should be corrected with controlled water addition.

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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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