Thermal expansion of morphologically textured short-fiber composites

Abstract

We studied, both experimentally and theoretically, the thermoelastic response of short-fiber composites with a preferred orientation of the short fibers, i.e., a morphological texture. Our theoretical efforts are general, being applicable to any composite system with constituents that exhibit linear thermoelastic response. We propose a relatively simple micromechanics model to predict the thermal expansion coefficient (CTE), and give simple, easily used, results for orientation distributions of practical significance. We also present a convenient approach to represent the effects of texture on thermal expansion of short fiber composites, namely, a texture map. Our experimental efforts focus on a series of extruded SiC/Al short-fiber composites that we have fully characterized. This includes measurement of the complete set of elastic constants, the volume fraction, and the fiber orientation distribution function (ODF) using neutron diffraction. We measured the axial and transverse components of the overall CTEs of these composites using a quartz-rod dilatometer. Predictions are in good agreement with measurements.

Thermal expansion behaviour of high performance PEEK matrix composites

“…For example, it is desired to match the out-of-plane CTE of the PCB with copper (∼17×10 −6 • C −1 ). Hence, the mismatch between the CTE of the two adjacent surfaces can lead to cracking and failure of solder connections [23][24][25]. In view of these data the present composites have importance in commercial use.…”