Nickel Superalloys FeCl₃+HCl

Chemical Etching Formula
Nimonic 90 with FeCl₃+HCl

This reference describes how Nimonic 90 responds to the FeCl₃+HCl etching formula. At a bath temperature of 56°C and concentration of 48 °Bé, the recipe holds an etch factor of about 2.38 and a typical production yield of 94.9%. 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
48 °Bé Concentration
1.450 Specific Gravity
56 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.1-0.3 mm Thickness Range
0.20 mm Typical Thickness
0.12-0.65 m/min Conveyor Speed Range
0.21 m/min Typical Speed
120-360 μm Min Hole Ø Range
100-300 μm Min Line Width Range
21-63 μm Undercut Range
2.38 Etch Factor (EF)
94.9% Typical Yield (94.6-95.2%)

Why FeCl₃+HCl for Nimonic 90?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like Nimonic 90. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on Nimonic 90 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 56°C and 48 °Bé. Conveyor speed spans 0.12-0.65 m/min over the 0.1-0.3 mm thickness band; the typical operating point is 0.21 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 Nimonic 90 at through etch (double-sided), plan for a minimum hole diameter in the 120-360 μm range and a minimum line width in the 100-300 μm range, depending on the chosen sheet thickness within 0.1-0.3 mm. The etch factor of ~2.38 and undercut range of 21-63 μm determine how much the mask must be biased to land the finished dimension on target.

Design Rule Summary
• Minimum hole diameter range: 120-360 μm
• Minimum line width range: 100-300 μm
• Single-side undercut range: 21-63 μm
• Typical etch factor (EF): 2.38

Yield & Production Economics

This formula delivers a typical yield of 94.9% (range 94.6-95.2%). 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 FeCl₃+HCl formula on Nimonic 90 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 600 FeCl₃+HCl Through etch (double-sided) Inconel 601 FeCl₃+HCl Through etch (double-sided) Inconel 625 FeCl₃+HCl Through etch (double-sided)

Frequently Asked Questions

Single-side undercut ranges 21-63 μm depending on thickness and dwell time. When sizing the photomask for a finished feature on Nimonic 90, subtract twice the expected undercut from the target width so the etched dimension lands on specification.

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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