Thermal Expansion - Steel Vs Fibreglass

[MadDog88]

Can somebody please give me some general figures on the difference in thermal expansion coefficients between steel and fibreglass. I would have thought steel had a higher coefficient but I have been told otherwise and can’t find any solid data myself. Thanks in advance.

 

[CoryPad]

Go to Matweb at:

http://www.matweb.com

For a general thermoset polyester Sheet Molding Composite (fiberglass material used for automobile panels) they list a CTE of 24 - 40 µm/m-°C. For a typical carbon steel, it is 12.2 µm/m-°C.

The reason for this is "fiberglass" has discontinuous reinforcement and incomplete reinforcement wetting. This means the thermal expansion is influenced heavily by the matrix properties, which are low for polymers.