News

Unobtanium Goes to Work!

By: J.A. Monroe

The struggle to keep lenses in focus while withstanding temperature change is nothing new. As an engineer, you may not care why temperature change pushes a lens assembly you are designing out of focus, you just care about finding a solution.

What happens when you’ve tried all of your traditional solutions and you still need two lens cells to come closer together when temperature increases? You could create a barrel-in-barrel design, but that would add complexity and component count while making the whole system larger and heavier. There is a simpler solution with a material that shrinks when heated.

ALLVAR Alloy 30, the first commercially available material with negative thermal expansion.

While modeling and calculations are helpful, they pale in comparison to seeing actual results. Above is an optic demonstrator which includes a lens assembly designed to require a negative thermal expansion material between two lens cells in order to maintain optimum focus. We used it to compare the performance of ALLVAR Alloy 30 to other metals like Aluminum, Titanium, and Invar.

Looking at the image below, ALLVAR Alloy 30 maintains the best focus as the temperature increases from 29° to 65°C. Watch the full video here.

For those that prefer more technical detail, shown below are the Modulation Transfer Function (MTF) values versus temperature for each image spot for the four materials tested. The Aluminum and Ti6Al4V (Ti64) show very sharp peaks associated with rapid drop offs in performance above and below an optimal operating temperature. The Invar shows excellent stability between 20°C and 50°C, but MTF drops off well below 60% above and below optimal operating temperature. The ALLVAR Alloy 30 material displays a much smoother response and excellent stability throughout with a small decrease from 85% MTF at -10 °C to 60% MTF at 70°C.

 

With ALLVAR Alloy 30, you have another tool in your engineering toolbox. The novel metal that shrinks when heated and expands when cooled. Solve your focusing dilemmas today.

 

 

 

 

Unobtanium Has Arrived!

By: Amy Zelazny

Do you have a problem maintaining the performance and structural integrity of your opto-mechanical design over a wide temperature range? Would a material with little or even negative CTE solve this problem?

We can help: ALLVAR Alloy 30, offered by ALLVAR Alloys:

  • Has a longitudinal Coefficient of Thermal Expansion of -30.0ppm/°C
  • Has a positive CTE in the radial direction (similar in magnitude to Aluminum), allowing for compliant mounting of optical elements
  • Exhibits many of the properties of Titanium
    • Alloy 30 can be machined like any other metal, tolerances of 0.001” are easily achievable
    • Just as with Aluminum, Alloy 30 can be anodized to provide maximum control of stray light within your lens assembly and optical system
  • Is offered in both round bar and tube formats. It is a natural fit for the design and fabrication of lens stack spacers, lens barrels, and lens to focal plane stand-offs.

The inclusion of ALLVAR Alloy 30 in your next opto-mechanical design can lead to:

  • Lower optical element count due to successful passive mechanical athermalization
  • Simplified mechanical geometry leading to weight savings
  • Reduced complexity and cost throughout your supply chain and manufacturing process

Specifically targeting fixed-focus LWIR objectives/cameras, the addition of ALLVAR Alloy 30 can eliminate nested barrel structures and complex compensation mechanisms, providing passive mechanical athermalization for maintenance of optimum image quality from -40°C to +70°C and beyond.

Don’t miss out on an opportunity to use an exciting new material that will increase the efficiency of your opto-mechanical design cycle, contact ALLVAR Alloys today.

ALLVAR Alloys Announces ALLVAR University Series of Online Video Sessions

Online Video Sessions Provide Education and Insight on Negative Thermal Expansion Benefits

College Station, TX – ALLVAR, a manufacturer of revolutionary alloys that exhibit negative thermal expansion (NTE), has announced a series of educational videos, called ALLVAR University, that showcase a particular application, calculation or considerations when designing assemblies with a component manufactured with NTE ALLVAR Alloys.

ALLVAR Alloys have unique thermal expansion properties. They shrink when heated and expand when cooled, a phenomenon known as negative thermal expansion (NTE). These patented alloys are typically coupled to a traditional positive thermal expansion metal to counter their expansion properties, making the overall structure athermal.

Dr. James A. Monroe, Founder of ALLVAR, designed this educational series to help people understand the potential of negative thermal expansion alloys, especially for athermalizing assemblies or structures that are exposed to extreme temperature fluctuations. “Knowing how the alloy behaves across a large temperature shift can enable optic designers to negate any thermal degradation of performance.”

He added that ALLVAR Alloys are being used in complex assemblies by NASA for space telescopes or as a simple way to maintain constant force in fasteners over temperature. Monroe added, “We manufacture NTE washers that minimize the likelihood of a bolt loosening when exposed to repeated temperature cycles. A constant force is achieved over temperature just by replacing a normal washer with an ALLVAR Alloy washer.”

The videos are each approximately 8 minutes long and topics covered will range from applications in IR optics and optical systems to calculating various scenarios to achieve zero overall thermal shift. Follow the company on Facebook or LinkedIn for the bi-weekly videos or visit the video library on their web site to get started.

About ALLVAR Alloys:
Founded in 2014, ALLVAR develops and manufactures ALLVAR Alloys that exhibit negative thermal expansion (NTE) properties. These alloys compensate and eliminate detrimental effects that thermal expansion has on many applications, such as IR optics, petroleum and chemical exploration and processing, remote weather or atmospheric monitoring, and space-based instruments. The company provides NTE washers and spacers, as well as bars and tubes for mounting struts or rails for commercial applications in addition to their custom contract work. Visit the web site at http://www.allvaralloys.com or follow the company on Facebook or LinkedIn.

ALLVAR Wins SBIR Phase I Award from NASA for High Temperature Alloy Development

ALLVAR Awarded NASA SBIR Phase I Grant for Development of High Temperature Alloy

New alloy could improve the lifetime and reliability of high-temperature sensors and structures in space expeditions

College Station, TX – ALLVAR, a manufacturer of revolutionary alloys that exhibit negative thermal expansion (NTE), has been awarded a NASA SBIR Phase I Grant to develop a new high temperature NTE alloy. The new alloy, ALLVAR Alloy-HT, is expected to improve the reliability and reusability of future high temperature planetary and lunar mission systems by compensating the expansion effects of other materials.

ALLVAR expects this new alloy to withstand temperatures from -200°C to 500°C, enabling NASA’s reusable moon mission hardware and the exploration of Venus with reliable and stable instruments.

ALLVAR alloys have unique thermal expansion properties. They shrink when heated and expand when cooled, a phenomenon known as negative thermal expansion (NTE). The patented NTE alloys are typically coupled to a traditional metal to counter their positive expansion properties, making the overall structure athermal.

Dr. James A. Monroe, Founder of ALLVAR Alloys, said this new alloy would solve a key problem for NASA’s space exploration: Longevity. “The high temperatures experienced on Venus can quickly push critical instruments and sensors out of alignment while thermal cycles on the moon reduce system reliability due to the continual expansion and contraction of components. At some point, the sensors stop working or the structures fail.” He added that other applications, including those requiring constant force load fasteners, high temperature engines or precision optics, could also benefit from this new alloy.

This is the third NASA SBIR award ALLVAR has received and the first for high-temperature alloy development. The company is currently developing structural supports for space telescopes with picometer level stability made in part with previous ALLVAR Alloys developed from SBIR grants.

About ALLVAR Alloys:

Founded in 2014, ALLVAR Alloys develops and manufactures alloys with negative thermal expansion properties. These alloys compensate and eliminate detrimental effects that thermal expansion has on many applications, such as IR Optics, petroleum and chemical processing, remote weather or atmospheric monitoring, and space-based instruments. The company provides NTE washers and spacers, as well as bars and tubes for mounting struts or rails for commercial applications in addition to their custom contract work. Visit the web site at www.allvaralloys.com or follow the company on LinkedIn.

ALLVAR wins NASA SBIR Phase II award

ALLVAR alloys has been awarded a NASA Small Business Innovative Research Phase II grant for “Ultra-stable ALLVAR Alloy Strut Development for Space Telescopes.”

This NASA SBIR Phase II proposal was in response to the need for Ultra-Stable Telescope Structures and is designed to evaluate ALLVAR Alloys for their potential as metering and support structures for optics that are critical to NASA’s future missions. Telescopes used for astrophysics, exoplanet, and planetary studies require picometer stability over several minutes to hours. Building large support structures with picometer level stability is a challenge with currently available materials due to their brittle nature in the case of Zerodur and ULE or their requirement to have tight thermal control in the case of SiC or carbon fiber composites. ALLVAR Alloys offer a new material solution for thermally stable structures. They exhibit negative thermal expansion and can compensate for the positive thermal expansion of other materials to stabilize a telescope

Website Redesign

A lot has happened at ALLVAR in just a short time! While we’ve been continuously striving towards prototype development, the team realized that the old website needed a complete overhaul. After a little practice, we were able to put together a new site that better tells about our revolutionary negative thermal expansion metal and the team behind it.

We hope you enjoy the new site!

ALLVAR secures NSF SBIR Phase II award

The National Science Foundation (NSF) has awarded ALLVAR with a Small Business Innovative Research Phase II grant. The intellectual merit of this project lies in a new method to exhibit unprecedented control over thermal expansion properties in metal alloys.

The discovery of the tailoring effect or “programmed” thermal expansion of a bulk metal to match that of other common materials (metals, polymers, and ceramics) will change the way scientists and engineers design for thermal compensation. These alloys can also be tailored not to expand or contract with temperature changes and even be made to shrink when heated.

The total awarded amount of the NSF SBIR Phase II is $750,000.