ALLVAR Alloy 30 harnesses a unique negative Coefficient of Thermal Expansion (CTE) to expand as other materials contract, effectively compensating for thermal mismatch and maintaining constant-force joint stability. This negative CTE (-30 ppm/°C at 25°C) causes greater contraction in one direction than aluminum expands over the same temperature range. The negative CTE compensates for the expansion and contraction of other materials. 

Yes! ALLVAR Alloys are titanium-based alloys that are corrosion-resistant, non-magnetic, and can be welded to Ti-6-4 and other ALLVAR Alloy components.

No, the elements in ALLVAR alloys are non-toxic.

Currently, we provide:

• Solid bar up to 2.25″ in. round
• Tube up to 3 in. OD, depending on the wall thickness
• Rod as small as 1/8 in. diameter
• Constant force-load washers for fasteners in temperature variant environments

Absolutely. ALLVAR Alloy 30 is often used for compensating for thermal mismatch in deep cryogenic environments. Please check our our ALLVAR Alloy Preload calculator to see this in action down to 20K (-253°C) or reach out to us for more information.

Want to go even colder? That’s cool. Our measured CTE data ends at 20K, but that doesn’t stop ALLVAR from performing even colder. 

ALLVAR Alloys can be used to achieve net zero linear thermal expansion. Negative thermal expansion ALLVAR Alloys can compensate for positive thermal expansion components along an axial direction. The CTE of an assembly can be tuned to a specific value, negative, positive, or zero CTE. Learn more in this video or contact us to talk to one of our thermal expansion experts.

There are many applications and products that negative CTE ALLVAR Alloys can improve! Some of the most notable are space telescopes, optics used in extreme environments, lens housings, cryostats and cryogenic equipment, quantum computing, and unique scientific instruments. Negative thermal expansion alloys are novel, so if your application is not on the list, we would love to help!

Yes! If you can machine titanium, you can machine ALLVAR Alloys. They can be machined into rods, struts, tubes, or other custom components.

No. Additional processing is not needed to achieve ALLVAR Alloys novel, patented negative thermal expansion capabilities.

ALLVAR Alloys are non-magnetic and have similar magnetic properties to other titanium-based alloys

Yes, ALLVAR Alloys are on missions today. ALLVAR Alloy 30 is currently on the Nancy Grace Roman Space Telescope’s Coronagraph Instrument, Alloy 30 washers sit in the cryogenic sub-assembly and hold delicate pyrolytic graphite thermal straps at the right contact pressure. If you have an aerospace application and are considering Alloy 30, contact us and we will discuss how ALLVAR can help!

Since ALLVAR Alloys are made of true metals, they behave like all other metals do in a vacuum. There is no moisture or other material component that would cause problems from outgassing.

Yes! We have successfully welded ALLVAR Alloys to Ti-6-4 and other ALLVAR pieces.

We have two alloys currently available, and each alloy has a different operating temperature.

• ALLVAR Alloy 30 operates from deep cryogenic temperatures to ~100 °C.
• If you need to go slightly above 100°C, let us know. We have worked on higher temperature NTE alloys and may have a solution for your application.

Let us know if you have an application outside of these temperature ranges. We are material scientists at heart and would love the opportunity to develop a higher temperature NTE alloy.

No, ALLVAR Alloys are anisotropic, meaning if the bar shrinks in length, it will grow in the radial direction. The growth is consistent and runs about 2 ppm/°C more than the shrinkage in the length. For example, if the ALLVAR bar has a negative 30 ppm/°C in the length, it will have a positive 32 ppm/°C in the radial direction.

Yes, ALLVAR Alloys are corrosion resistant. ALLVAR Alloys are titanium-based and are comparably corrosion resistant to titanium.

While the ALLVAR team has never coated them, we have been told by our partners that it can be coated like titanium.

We have never polished it internally, but it will polish like titanium, which we have been told by our partners is a bit gummy.

While we have not studied this directly, we have never observed a change in CTE characteristics or performance during the normal handling experienced in a machine shop environment.

No, ALLVAR Alloys do not absorb moisture from the surrounding environment.

ALLVAR Alloys are a custom material with higher touch times than many standard materials. The costs are higher than standard titanium, but lower than many exotic materials. Reach out to get a quote for your specific project.

ALLVAR Alloys are designed for companies that have extreme performance requirements and need a customized solution for performance critical applications. ALLVAR Alloys are for previously unachievable size, length, and weight requirements, where plastic titanium, or aluminum will not make the cut.

We have statistically significant A-, B- and S- Basis design-allowables for ALLVAR Alloy 30 like those found in the material Metallic Materials Properties Development and Standardization (MMPDS). We rigouresly test and develop our products to to meet the stringent requirements that many of our customers require.  Please reach out to request access to these design allowables.

ALLVAR Alloys are new. They are not manufactured to any ASTM or other governing body’s standards because there are no specifications to compare it to. According to these standards, there is no such thing as a titanium or any metal that shrinks when it gets hot!

INVAR’s material cost does not reflect the cost of the machining and processing. INVAR requires multiple rounds of heat treating to achieve its near-zero CTE properties in machined parts, greatly increasing its processing cost. While INVAR may be a less expensive near-zero CTE material than ALLVAR Alloys, there are many downsides to using it. INVAR is sensitive – not to mention heavy. It is also magnetic and very corrosive. Unlike INVAR, ALLVAR Alloys derive their negative CTE properties through a unique blend of processing and chemistry. ALLVAR Alloys are also lightweight, corrosion-resistant, non-magnetic, and don’t require extensive heat treatments. Learn more at our ALLVAR vs Invar Blog.

ALLVAR Alloy 30 is not available in powder form for 3D printing. 

ALLVAR sells directly to the end user – we do not have any distributors currently.

Please contact us! We are just as much a team of material engineers as we are material manufacturers. We pride ourselves on being a transparent and solution-oriented team that will tell you if ALLVAR Alloys are right for you. If ALLVAR Alloys are not right for you, we are more than happy to suggest an alternative solution that will fit your needs.

Engineers have joked that a negative thermal expansion material is unobtanium. We are pleased to announce that unobtanium has arrived! We can provide negative thermal expansion ALLVAR Alloys for your project today.