Why Galvanic Corrosion Testing Matters Across Industries

When two dissimilar metals are in contact and exposed to a corrosive environment, one often corrodes at the expense of the other—a phenomenon known as galvanic corrosion. Galvanic corrosion must be considered in nearly any design where metallic components are used, such as aerospace applications, automotive design, marine, renewable energy, defense, infrastructure, and medical devices.

Whether you’re working on a ship hull, electric vehicle battery enclosure, offshore wind turbine, or a structural assembly, galvanic corrosion can quietly undermine your system’s integrity. At Secat, Inc., our corrosion testing capabilities help industries identify these risks early—before materials fail in the field.

This case study explores the galvanic corrosion relationship between titanium alloy Ti-6Al-4V and aluminum alloy AA 2024-T3, two widely used metals in demanding environments.

Case Study Overview: Why These Materials?

Ti-6Al-4V, a high-performance titanium alloy, is known for its excellent strength-to-weight ratio, corrosion resistance, and durability in extreme environments. It’s commonly used in aircraft components, surgical implants, chemical processing equipment, and marine hardware.

AA 2024-T3 is a high-strength aluminum alloy prized for its fatigue resistance and good machinability. It’s frequently found in aircraft structures, automotive parts, marine applications, and even bridge panels.

When these two metals are used together in real-world products like aerostructures, defense vehicles, or rockets, it’s important to understand how they interact with each other. Aluminum is more likely to corrode when it’s in contact with titanium, especially in wet salty environments. If the materials aren’t carefully managed or protected, the aluminum part can corrode much faster than expected—leading to damage, safety concerns, or expensive repairs.

A well-known example comes from the Boeing 787 Dreamliner. The aircraft was designed with a much higher percentage of carbon fiber composites, which improved efficiency but created new corrosion risks. The graphite in the composites reacts strongly with aluminum, causing rapid galvanic corrosion at the joints. To overcome this, Boeing replaced many of those aluminum joints with titanium alloys, which are far more compatible with carbon fiber. This design change illustrates the same principle studied here: the wrong material pairing can shorten a structure’s life, while the right one can dramatically improve durability.

Testing Setup: Simulating Real-World Corrosive Conditions

To explore this interaction, we machined both alloys into cylindrical samples measuring 6.7 mm in diameter.

Prior to testing, the samples underwent ultrasonic cleaning in acetone to remove any contaminants. They were dried in a vacuum desiccator and weighed using a precision lab balance. A black polymer coating was then applied to each sample to expose exactly 30 mm of surface area to the testing solution.

Corrosion testing was performed in acidified synthetic seawater (ASTM G85 A3 solution) which simulate harsh marine environments and tested according to ASTM G71-81. After exposure, the samples were stripped of their coatings, cleaned, dried, and reweighed to measure corrosion effects.

Results: Measuring Corrosion in Controlled Conditions

Visual Observations

  • Before Testing: Samples were clean, coated, and polished.
  • During Testing: Both samples were fully submerged in synthetic seawater.
  • After Testing: Noticeable corrosion was visible on the aluminum alloy, while the titanium showed minimal surface change.

Quantitative Findings

Using ASTM G102, we calculated mass loss rate (MR) from corrosion current density (icorr).

Here’s a summary of the test data:

Material Initial Weight (g) Final Weight (g) Weight Loss (g) Weight Loss (%)
Ti-6Al-4V 6.6471 6.6470 0.0001 0.0015%
AA 2024-T3 3.6921 3.6879 0.0042 0.1138%
  • Corrosion Current Density (icorr): 0.0172 mA/cm²
  • Mass Loss Rate: 1.44341 g/m²·day
  • Mass Loss per Test (Al): 0.00023 g

Interpretation: A Clear Anodic-Cathodic Relationship

In this pairing, AA 2024-T3 functioned as the anode, meaning it corroded preferentially, while Ti-6Al-4V acted as the cathode, remaining largely unaffected. This confirms widely accepted galvanic behavior: aluminum alloys are more active (less noble) than titanium alloys and therefore more prone to corrosion when coupled in conductive environments.

Understanding this dynamic is crucial when these metals are used together in real-world structures. Without proper electrical insulation or surface treatment, the aluminum component will corrode faster, potentially compromising the integrity of the entire system.

From Aerospace Lessons to Everyday Design Challenges

The Boeing 787 is just one example of how galvanic corrosion drives design decisions. The same issue surfaces in other industries every day.

In the automotive sector, lightweight aluminum battery enclosures may be paired with stronger steel or titanium fasteners. Road salt accelerates galvanic reactions, meaning poor material choices can reduce lifespan or even create safety concerns. In the marine and offshore world, saltwater exposure makes the wrong combination of metals in ships, naval defense systems, or offshore wind turbines especially vulnerable.

Infrastructure projects face similar risks: bridges, cladding systems, and fasteners often mix aluminum with stainless or titanium, and if left unprotected in humid or coastal environments, galvanic corrosion can quietly shorten service life. The energy sector also feels the impact—solar panel frames, wind towers, and transmission systems are exposed year-round to rain, salt spray, and pollutants, which accelerate corrosion when dissimilar metals meet. Even in medical devices, titanium’s durability makes it ideal, but when paired with aluminum in surgical tools or support structures, corrosion risks must be carefully managed for patient safety.

Across industries, the story is the same: material selection isn’t just about strength or weight—it’s about compatibility. Just like Boeing had to rethink its design choices, engineers in every field must account for galvanic interactions to ensure durability and reliability.

How Secat Can Help

At Secat, Inc., we help engineers and manufacturers across industries make better material decisions through advanced corrosion testing, metallurgical analysis, and failure investigation.

Our lab can simulate harsh environments using industry-recognized standards or customer specific procedures, so you can understand how your components will behave before they enter the field. We offer tailored testing programs, interpret complex data into actionable insight, and support product teams in designing with confidence.

Whether you’re facing a materials challenge or want to validate a new design, we’re here to help.

Ready to Solve a Corrosion Challenge?

If you’re working with metals or facing unexpected corrosion problems, let’s talk. Secat can test your components under controlled conditions and help you mitigate corrosion before it leads to real-world failure.

Contact our Secat team today to learn more about our corrosion testing services or to start a project.