Aluminum Alloys FeCl₃+HCl

Chemical Etching Formula
Al6101 with FeCl₃+HCl

This reference describes how Al6101 responds to the FeCl₃+HCl etching formula. At a bath temperature of 42°C and concentration of 34 °Bé, the recipe holds an etch factor of about 2.52 and a typical production yield of 97.2%. It is intended as engineering reference data for design, sourcing, and process planning.

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.

FeCl₃+HCl Etchant System
34 °Bé Concentration
1.290 Specific Gravity
42 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.1-0.5 mm Thickness Range
0.25 mm Typical Thickness
0.12-1.08 m/min Conveyor Speed Range
0.32 m/min Typical Speed
120-600 μm Min Hole Ø Range
100-500 μm Min Line Width Range
20-99 μm Undercut Range
2.52 Etch Factor (EF)
97.2% Typical Yield (96.5-97.5%)

Why FeCl₃+HCl for Al6101?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like Al6101. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on Al6101 is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

The process window for this FeCl₃+HCl formula centres on 42°C and 34 °Bé. Conveyor speed spans 0.12-1.08 m/min over the 0.1-0.5 mm thickness band; the typical operating point is 0.32 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

Design rules for this recipe: hole diameter 120-600 μm, line width 100-500 μm, single-side undercut 20-99 μm — all as a function of thickness across 0.1-0.5 mm. The higher the etch factor (this formula holds about 2.52), the tighter the achievable tolerance. Below the minimum feature sizes, yield falls off steeply, so treat those numbers as hard floors rather than targets.

Design Rule Summary
• Minimum hole diameter range: 120-600 μm
• Minimum line width range: 100-500 μm
• Single-side undercut range: 20-99 μm
• Typical etch factor (EF): 2.52

Yield & Production Economics

Typical mass-production yield for Al6101 in the FeCl₃+HCl system is 97.2%, within an observed range of 96.5-97.5%. The dominant yield-loss modes are photoresist pinhole defects and rinse-water contamination. Improving incoming sheet quality and photoresist coating consistency gives the highest yield-improvement leverage for this formula.

Typical Applications

Al6101 etched with this recipe typically ends up in lightweight RF shields, heat-spreader masks, nameplates, decorative trim, and lightweight structural lattices. 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 Aluminum Alloys Formulas

Other formulas in the same material family.

Al1060 FeCl₃+HCl Through etch (double-sided) Al1060 FeCl₃+HCl Through etch (double-sided) Al1100 FeCl₃+HCl Through etch (double-sided) Al2014 FeCl₃+HCl Through etch (double-sided) Al2017 FeCl₃+HCl Through etch (double-sided) Al2024 FeCl₃+HCl Through etch (double-sided)

Frequently Asked Questions

Spent FeCl₃+HCl bath contains dissolved Al6101 ions and depleted oxidizer. Standard practice is chemical or electrolytic regeneration to recover activity, plus periodic decanting of metal-rich sludge for off-site recovery. Treatment to neutral pH with metals precipitation is the minimum before any discharge, and requirements vary by jurisdiction.

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WET Etched runs production wet chemical etching lines using the FeCl₃+HCl chemistry. Send us your part drawing and quantity for a full process quote.

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