Browsing by Author "Vekinis, G."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Novel Hybrid Ablative/Ceramic Layered Composite for Earth Re-entry Thermal Protection: Microstructural and Mechanical Performance(2015-04) Triantou, K.; Mergia, K.; Marinou, A.; Vekinis, G.; Barcena, J.; Florez, S.; Perez, B.; Pinaud, G.; Bouilly, J. M.; Fischer, W. P.P.; EXTREMAT; POLIMEROSIn 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 ASTERM™ lightweight ablative material with Cf/SiC (SICARBON™) 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%.Item Performance of cork and ceramic matrix composite joints for re-entry thermal protection structures(2017-01-01) Triantou, K.; Perez, B.; Marinou, A.; Florez, S.; Mergia, K.; Vekinis, G.; Barcena, J.; Rotärmel, W.; Zuber, C.; de Montbrun, À.; de Montbrun, Montbrun; POLIMEROS; EXTREMATIn view of spacecraft re-entry applications into planetary atmospheres, hybrid thermal protection systems based on cork and ceramic matrix composites are investigated. Joints of NORCOAT LIÈGE cork with C/Csingle bondSiC ceramic matrix composite were fabricated using a) high temperature commercial inorganic adhesives and b) in-situ polymerization of the cork on top of the CMC. Mechanical shear tests under ambient conditions and in liquid nitrogen are carried out. The ultimate shear strength of all the adhesive joints at room temperature varies between 0.52 and 0.78 MPa and is similar to that of the in-situ joints. At liquid nitrogen temperature the shear strength is enhanced by up to 80%, but the ultimate shear strain decreases up to 55%. The failure mode is discussed for the two types of the fabrication procedure.