Chemical Etching Formula
Nimonic 90 with FeCl₃+HCl

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.

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.

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.

Process Equipment & Material Reference

Production of Nimonic 90 parts using the FeCl₃+HCl formula described above runs on a biomedical blade etching machine configured for through etch (double-sided). The bath chemistry, conveyor speed, and rinse cascade detailed on this page reflect the operating profile we use on a live spray-etching line for this alloy.

For a broader treatment of the material itself — alloy variants, surface preparation, and process limits across thickness ranges — see our Nickel chemical etching guide. That overview complements the formula-specific bath and conveyor data on this page.

Production Use Cases for This Formula

Production examples for the Nimonic 90 / FeCl₃+HCl recipe span automotive horn mesh etching, high-speed air-intake mesh for hair dryers, and ultrasonic mesh for robotic vacuum cleaners. In every case, the etch factor and undercut figures on this page are the dominant tolerance drivers — bath maintenance discipline matters more than equipment headline rating.

Adjacent applications usually transfer onto this same formula with no chemistry change, sometimes only a conveyor speed tweak. Drop a drawing and a target volume and we will return a process card built off the parameters on this page.

Other Metals Etched with FeCl₃+HCl

The FeCl₃+HCl chemistry is also documented for these alloys.

More Nickel Superalloys Formulas

Other formulas in the same material family.

Frequently Asked Questions