Carbon fiber is rapidly becoming one of the choice materials in the field of metrology due to its high stability and low thermal expansion. In applications where thermal changes will move comparable metal measurement and alignment tools out of tolerance due to expansion or contraction of the material, carbon fiber will remain virtually unchanged over a wide temperature range. A standard carbon fiber part can readily be made with a CTE of 1.5 x 10-6 /K, or approximately the same as Invar steel, making it an ideal candidate for both metrology tools, as well as scientific equipment (for example, telescope lens support structure or mounting plates for lasers and mirrors).
Customized carbon fiber components can be designed with even lower CTE values down to 5 x 10-7 /K by preferentially aligning high modulus uni-directional prepregs, thus creating a part that has tailored, albeit varying, CTE values along different axes. One example of this is support beams for x-ray cyclotron sensors and equipment, where the majority of the carbon fibers are aligned along a single axis with the goal of reducing the CTE in one direction as much as possible. Although the CTE in the orthogonal direction becomes higher (i.e. it is sacrificed to a certain degree), in these applications it is often necessary to bring the vertical CTE component as close to zero as possible to prevent signal noise due to temperature fluctuations.
Dragonplate off-the-shelf materials, such as uni-directional prepreg sheets, roll-wrapped and braided tubes, and other structural shapes can help you meet your metrology and low CTE design needs. If your application demands a custom laminate or modified geometry, contact us either by phone or email. The engineers at Dragonplate are here to help.
If your equipment will experience excessive temperatures, DragonPlate offers high temperature carbon fiber that can withstand 500F degree temperatures for extended periods of time. Additionally, this material can survive extreme temperatures, such as the direct exposure to a propane torch for 30 to 60 seconds with only a minor reduction in stiffness.