Зеленеет ли титан?

Worried your titanium parts will discolor? Cheaper metals often turn green, causing costly failures. Real titanium’s properties prevent this, ensuring long-term stability and a professional look.

No, pure titanium does not turn green. A stable, self-healing oxide layer¹ forms on its surface, protecting it from reacting with elements like water or air. This strong barrier prevents the type of corrosion that causes green discoloration on other metals like copper.

That is the short answer. But you probably need more details to feel confident when speaking with engineers or clients. For example, what about rust, and how can you be sure the material you specify won’t stain someone’s skin? We need to look closer at what makes titanium so different from other metals. Let’s explore these questions so you can make the right choice for your project.

Does titanium rust or turn green?

Choosing materials for harsh environments is tough. The wrong metal can corrode and fail, causing huge problems. Let’s confirm if titanium really stands up to rust and corrosion.

No, titanium does not rust or turn green. Its protective passive layer, titanium dioxide (TiO₂)², instantly reforms if scratched. This prevents oxygen and water from reaching the base metal, stopping both rust (iron oxide) and green corrosion (copper oxide) from forming.

The key to titanium’s performance is a thin, invisible layer of titanium dioxide (TiO₂) on its surface. This layer is extremely stable and passive. If you scratch the metal, a new protective layer forms instantly upon contact with air. This self-healing ability is why titanium resists corrosion so well. At my plant, we test our materials according to global standards like ASTM B265, which confirms this quality. Our internal salt spray tests consistently show zero corrosion on titanium parts.

A long-term client in marine engineering confirmed this. They use our titanium valves in high-salinity water. After eight years in service, he told me the valves are still silver-gray, with no signs of green staining or rust. We see the same reliability in medical implants, which must last for decades inside the human body without corroding.

What type of metal won’t turn skin green?

Ever seen skin turn green from a piece of jewelry? This reaction is a big problem for any products that come into contact with the body, from consumer goods to medical devices.

Medically-implantable metals like titanium, platinum, and surgical stainless steel won’t turn skin green. These metals are biocompatible, so they don’t react with skin oils or sweat. This prevents them from releasing the metal ions that cause discoloration and allergic reactions. Titanium is especially safe.

Skin turns green because of a chemical reaction, usually with copper. When copper or nickel alloys react with sweat and skin oils, they create salts that leave a green stain. This is often a sign of a mild allergic reaction, which is unacceptable for many products. To avoid this, you need a truly biocompatible metal. In my field, we rely on standards like ISO 10993³ to certify materials for medical use.

Titanium, especially medical-grade alloys like Grade 23 (Ti-6Al-4V ELI), is a top choice. I work with this grade often. It’s highly inert, which just means it doesn’t react with the human body. That’s why it’s used for critical applications like hip implants and pacemaker cases.

Safe vs. Risky Metals for Skin Contact

• Metals That Don’t Stain Skin:
  • Титан
  • Платина
  • Niobium
• Metals That Can Stain Skin:
  • Copper
  • Никель
  • Brass (a copper alloy)

A client who manufactures jewelry told me they switched to our titanium for their earring studs. After the switch, their customer complaints about skin reactions and green stains dropped to zero.

What turns titanium green?

You’ve heard titanium doesn’t turn green, but what if you see an example that does? This can be very confusing and might make you doubt the material’s quality or your supplier’s honesty.

Pure titanium does not turn green. Green discoloration happens for two main reasons. Either the part is a fake "titanium" alloy containing copper, or the real titanium has been coated with another metal. Harsh chlorine-based cleaners can also sometimes cause a surface stain.

Let me be very clear: real, pure titanium does not create its own green corrosion. If you see a green product being sold as "titanium," it is almost always one of two things.

First, and most commonly, it is counterfeit material. Some suppliers sell cheap alloys containing copper or nickel and falsely label them as titanium to charge a higher price. I have seen this happen with clients who bought low-cost parts from unverified sources. The copper in the fake alloy is what reacts with air and moisture, creating the green color.

Second, the part could have a surface coating. Sometimes, titanium is electroplated with copper for a specific aesthetic or electrical property. In this situation, it is the copper plating that turns green, not the titanium underneath.

Finally, very aggressive chlorine-based cleaners can sometimes leave a green or colored deposit on the surface. This isn’t corrosion of the titanium itself, but simply a chemical residue that can usually be wiped off.

Does real titanium tarnish?

You need a material that maintains its appearance for a long time. Tarnished parts look unprofessional and can suggest poor quality, which reflects poorly on your final product.

No, real titanium does not tarnish. Tarnish is a slow-forming layer of corrosion, common on metals like silver. Titanium’s passive oxide layer is non-reactive and extremely stable, which prevents this type of slow surface discoloration from ever happening.

Tarnish is what happens when a metal’s surface slowly reacts with elements in the air, especially sulfur. It creates a dull, dirty-looking film. You see it all the time on old silver cutlery or copper pipes. Titanium does not do this. Its protective titanium dioxide layer is just too strong and stable. It completely seals the metal off from the surrounding environment.

To prove this, we run aggressive salt spray tests in our lab here in Baoji, following the ISO 9227 standard. Even after 1,000 hours in a corrosive salt fog, our titanium samples look exactly the same as when they started. They keep their original metallic luster, unlike steel or silver samples tested alongside them. A client who makes aerospace components told me something similar. They use our Grade 5 titanium for parts on aircraft. He said that after 10 years in service, exposed to extreme temperatures and atmospheric conditions, the parts require no polishing or refinishing. They simply don’t tarnish.

• Silver: Tarnishes quickly, turning dull and then black.
• Copper: Tarnishes, turning brown and then green.
• Titanium: Does not tarnish. Stays bright and clean.

Заключение

In short, pure titanium does not turn green, rust, or tarnish. Its unique protective layer ensures long-term performance and a clean, professional appearance in any application you choose.