Nickel Superalloys FeCl₃+HCl

Chemical Etching Formula
Inconel 600 with FeCl₃+HCl

This page documents the reference wet chemical etching formula for Inconel 600 using the FeCl₃+HCl 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.

FeCl₃+HCl Etchant System
46 °Bé Concentration
1.430 Specific Gravity
52 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.05-0.5 mm Thickness Range
0.18 mm Typical Thickness
0.12-2.27 m/min Conveyor Speed Range
0.32 m/min Typical Speed
60-600 μm Min Hole Ø Range
100-500 μm Min Line Width Range
10-99 μm Undercut Range
2.52 Etch Factor (EF)
95.5% Typical Yield (94.5-95.8%)

Why FeCl₃+HCl for Inconel 600?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like Inconel 600. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on Inconel 600 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 52°C and 46 °Bé. Conveyor speed spans 0.12-2.27 m/min over the 0.05-0.5 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

Feature sizes scale with sheet thickness. For this formula the minimum hole diameter ranges 60-600 μm and the minimum line width ranges 100-500 μm across the 0.05-0.5 mm band, following the industry 1.2× (hole) and 1.0× (line) thickness rules. Single-side undercut ranges 10-99 μm, and the etch factor is about 2.52. Size your photomask by subtracting twice the expected undercut from each finished feature dimension.

Design Rule Summary
• Minimum hole diameter range: 60-600 μm
• Minimum line width range: 100-500 μm
• Single-side undercut range: 10-99 μm
• Typical etch factor (EF): 2.52

Yield & Production Economics

Expect a yield in the 94.5-95.8% range for Inconel 600 with FeCl₃+HCl, with 95.5% typical on a well-controlled line. Most rejects trace back to upstream coating and exposure rather than to the etch bath itself, so tightening photolithography control is usually the fastest path to a higher number.

Typical Applications

Parts produced with the FeCl₃+HCl formula on Inconel 600 are common in turbine-engine seals, high-temperature gaskets, and aerospace fluidic plates. 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 Nickel Superalloys Formulas

Other formulas in the same material family.

Hastelloy C-22 FeCl₃+HCl Through etch (double-sided) Hastelloy C-276 FeCl₃+HCl Through etch (double-sided) Hastelloy X FeCl₃+HCl Through etch (double-sided) Inconel 601 FeCl₃+HCl Through etch (double-sided) Inconel 625 FeCl₃+HCl Through etch (double-sided) Inconel 690 FeCl₃+HCl Through etch (double-sided)

Frequently Asked Questions

Typical mass-production yield is 95.5%, within an observed range of 94.5-95.8%. The leading yield-loss modes are photoresist pinhole defects and rinse contamination, so the fastest route to a higher number is tighter incoming-sheet and coating control rather than changes to the etch bath.

Need a Quote for This Process?

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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