Chemical Etching Formula
Inconel 718 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 Inconel 718?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like Inconel 718. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on Inconel 718 is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

Hold the bath at 56°C with concentration 48 °Bé (specific gravity 1.450). Across the 0.01-0.5 mm thickness range, conveyor speed runs from 0.12-44.23 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 3.49 m/min for 0.04 mm stock. Use redundant PID temperature control to hold the bath within ±1.5°C, and titrate at least once per shift.

Design Rules & Tolerances

When laying out artwork for Inconel 718 at through etch (double-sided), plan for a minimum hole diameter in the 8-600 μm range and a minimum line width in the 100-500 μm range, depending on the chosen sheet thickness within 0.01-0.5 mm. The etch factor of ~2.45 and undercut range of 1-102 μm determine how much the mask must be biased to land the finished dimension on target.

Yield & Production Economics

Expect a yield in the 94-96% range for Inconel 718 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 718 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

On the shop floor, this Inconel 718 + FeCl₃+HCl recipe is implemented on a wet chemical etching machine. The 56°C bath setpoint and 0.12-44.23 m/min conveyor range correspond to verified production envelopes on that equipment for through etch (double-sided).

The Nickel chemical etching guide reference goes one level above the recipe shown here, surveying the full thickness range, depth options, and common subgrades we run for nickel.

Production Use Cases for This Formula

Production examples for the Inconel 718 / FeCl₃+HCl recipe span stainless filtration mesh for vacuum cleaners, heat-dissipation vent etching for VC cooling, 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.

Designs that sit slightly outside this thickness or feature-size envelope are usually addressable by a sister formula in the same etchant family. The bath chemistry stays the same; the tuning shifts to conveyor speed and resist choice.

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