Chemical Milling: Precision Material Removal for Complex Geometries

Chemical milling is a subtractive manufacturing process that selectively removes material from metal surfaces using controlled chemical etching. This technique is ideal for producing intricate geometries, reducing weight, and adjusting part thickness without introducing mechanical stress or altering metallurgical properties. Widely used in the aerospace, defense, and electronics industries, chemical milling enables lightweight structural components and detailed surface modifications with high precision and repeatability.

The Chemical Milling Process: Key Steps

Surface Preparation: The metal surface is cleaned and masked with a chemical-resistant coating to define the areas for material removal.
Chemical Etching: The exposed areas are immersed in a carefully controlled etchant solution that dissolves metal at a predictable rate.
Rinsing and Neutralization: After the desired depth is achieved, the part is removed, neutralized, and rinsed thoroughly, typically with deionized water.
Maskant Removal and Final Cleaning: The maskant is stripped, and the part is cleaned to remove residues and prepare it for the next stage of processing.

Applications of Chemical Milling

Weight Reduction: Common in aerospace to lighten structural parts without compromising integrity.
Precision Surface Shaping: Producing pockets, grooves, and contours in titanium, aluminum, or specialty alloys.
Component Balancing: Fine-tuning parts like turbine blades or rotors by removing specific material volumes.
Surface Texturing: Creating controlled finishes for bonding or coating applications.

Importance of Water Quality in Chemical Milling

Water plays a critical role in rinsing and neutralizing parts during and after etching, directly impacting surface quality and process consistency.

Deionized (DI) Water Rinsing: Ensures no ionic contamination, improving downstream coating or bonding performance.
Closed-Loop Rinse Water Systems: Maintain high water purity standards while significantly reducing consumption and discharge.

Importance of Process Control in Chemical Milling

Tightly managing chemical concentrations, dwell times, and temperature is essential for precise, uniform material removal.

Consistency: Achieves uniform depth across complex geometries.
Quality: Prevents over-etching, under-etching, and surface pitting.
Efficiency: Reduces chemical waste, improves yield, and minimizes rework.

The Role of Equipment Design in Chemical Milling

AQUASGROUP chemical milling systems are engineered to deliver accurate and repeatable results while ensuring safe handling of corrosive chemistries.

Precision Chemistry Control: Automated dosing and monitoring maintain optimal etching conditions.
Durable Construction: Corrosion-resistant tanks, piping, and fixtures ensure long-term reliability.
Agitation & Circulation: Promotes even chemical action and temperature uniformity across the workpiece.
Integrated Rinse and Neutralization Systems: Improve workflow and prevent chemical carryover.
Safety & Containment: Includes fume extraction, overflow protection, and smart diagnostics for safe operation.

Proven Expertise Since 1986

Since 1986, AQUASGROUP has designed and built advanced metal finishing and water management systems with thousands of successful installations across the globe. Our systems are trusted by major aerospace, medical device, automotive and other industrial manufacturers for their precision, reliability, and ability to integrate seamlessly into demanding production environments. We offer engineered solutions that align with your quality, efficiency, and sustainability goals.