If you’re battling the effects of thermal expansion and contraction of metals consider Negative CTE for extreme environments.  Athermalization on optics is one of the biggest challenges designers face when dealing with extreme environments.  As materials get hot or get bitterly cold, the resulting stresses on the housings cause performance problems in optics.

Beyond optics, thermal stress caused by the different expansion and contraction of dissimilar materials can lead to failure. Bolted joints can lose their pre-load as temperature shift, reducing reliability, and effecting performance of assemblies. For example, within cryostats and cryocoolers, fastened items may lose their force load and become unfastened, losign alignment or positioning of valuable equipment or seals. ALLVAR Washers and Spacers can combat these challenging thermal issues with a simple drop-in replacement for traditional washers. These thermal compensating washers can maintain a constant-force load from room temperature to extreme cryogenic temperatures.

In optics applications, this dictates the need for elaborate housing designs and even bolt-on heating/cooling mechanisms to keep the optics within a manageable working environment.

Not anymore.

ALLVAR Alloys are the only metals in the world that reacts completely opposite of other materials. It shrinks when it gets hot, and expands when it gets cold, offering a passive solution to assemblies in extreme environments that can save weight, time, and money.

Alloy-30 offers a NTE (Negative Thermal Expansion) down to -30 ppm /  ℃, operating passively and reliably in extreme environments from 100℃ to cryogenic temperatures.

Could Alloy-30 be used to compensate for the positive CTE of other materials to ensure an improved performance of optics or instrumentation?

What can you do with a NEGATIVE CTE metal?  

Welcome to our world BELOW Zero.