Drawing No. EH–MT–007 // Engineering Materials
Carbon / Epoxy Composite Properties
Reviewed August 2026
IM7/8552 is a high-performance aerospace carbon/epoxy system. The displayed 0° properties demonstrate why composites must be described by fiber direction, layup, cure condition and environment rather than one isotropic material constant.
Representative properties
The stated basis, temperature and direction are part of the value. Switch units without changing the physical reference.
What changes these properties?
Engineering variability
- 0°, 90°, shear and laminate-level properties can differ by an order of magnitude or more.
- Moisture and elevated temperature reduce matrix-dominated properties.
- Layup, fiber volume, cure cycle, void content and defects control performance.
- There is no conventional homogeneous yield point or melting point for the cured thermoset composite.
Selection note
Representative of aerospace primary-structure composites where high specific stiffness and strength dominate, but laminate analysis and damage tolerance are mandatory.
Where a property is shown as qualitative rather than numeric, that is intentional: the selected source or the material physics does not justify a single comparable scalar.
How to interpret this material
Stiffness
Young’s modulus describes elastic stiffness. For crystals and composites, orientation can make one scalar modulus only a directional reference.
Strength / failure
Ductile metals can use yield and tensile strength. Brittle ceramics/semiconductors and anisotropic composites require fracture, flexural or directional strength descriptions instead.
Thermal response
Conductivity, heat capacity and expansion are temperature dependent. The last column is a melting or transition descriptor only where that physical concept is appropriate.
Technical sources
The database favors manufacturer, industry, government or academic technical references and labels secondary condition-specific datasets when a primary source does not expose a complete property set.