Novel Hybrid Ablative/Ceramic Layered Composite for Earth Re-entry Thermal Protection: Microstructural and Mechanical Performance

Abstract

In view of spacecraft re-entry applications into planetary atmospheres, hybrid thermal protection systems based on layered composites of ablative materials and ceramic matrix composites are investigated. Joints of ASTERMÔ lightweight ablative material with C f /SiC (SICARBONÔ) were fabricated using commercial high temperature inorganic adhesives. Sound joints without defects are produced and very good bonding of the adhesive with both base materials is observed. Mechanical shear tests under ambient conditions and in liquid nitrogen show that mechanical failure always takes place inside the ablative material with no decohesion of the interface of the adhesive layer with the bonded materials. Surface treatment of the ablative surface prior to bonding enhances both the shear strength and the ultimate shear strain by up to about 60%.

Infra-red and vibration tests of hybrid ablative/ceramic matrix technological breadboards for earth re-entry thermal protection systems

“…The screening was performed employing pull off tests and microstructure investigation of the interfaces. Furthermore, this selection was based on the results of the previous studies [5,6,13] employing thermal shock tests as well as mechanical tests at liquid nitrogen, room and elevated temperatures. The adhesives were supplied from Aremco Products, Inc. Their properties and composition are presented in Table 1.…”

“…The aim is to fabricate the hybrid ablative/ceramic structure, through adhesive bonding based on commercial high temperature inorganic adhesives is employed. In our previous work [6,7] appropriate adhesives were selected based on the microstructural characteristics and the thermomechanical performance of the joints.…”