EFFECTS OF THERMAL CYCLING ON MECHANICAL AND PHYSICAL PROPERTIES OF HIGH PERFORMANCE CARBON/EPOXY COMPOSITES APPLIED TO SATELLITE ANTENNA

摘要

The aim of this article was to investigate the effects of thermal cycling on mechanical and physical properties of high performance carbon/epoxy (M40J/BA204) composites applied to satellite antenna. The thermo-cycling (-196°C to 130 °C, 200 cycles) was performed on unidirectional composite and pipe composite. For unidirectional composite the changes in dynamic mechanical properties and thermal stability were characterized by dynamic mechanical analysis (DMA) and thermo gravimetric analysis (TGA), respectively. The evolution of surface morphology and surface roughness were observed by atomic force microscopy (AFM). Changes in mechanical properties including longitudinal tensile property, flexural property and interlaminar shear strength (ILSS) were measured. For pipe composite, changes in mechanical properties including tensile property and flexural property were measured. The results of unidirectional composite indicated that the thermal cycling could improve the cross-linking degree and the thermal stability of resin matrix to a certain extent and induce thermal stress, thereby leading to the interfacial de-bonding. The degradation in longitudinal tensile properties was caused by effects of the interfacial de-bonding. The changes in flexural properties and ILSS were affected by the cross-linking degree of the resin and the interfacial de-bonding. Even so the integrate mechanical property of pipe composite was almost constant after 200 times of thermo-cycling, which indicates that the pipe composites has good thermal stability and good mechanical stability.