This paper discusses the influence of humidity and landing energy on the 'adsorption/desorption' phenomena of friction debris obtained from carbon-carbon composite brake materials. Debris samples were collected from three discrete C/C materials during subscale dynamometer disc on disc type testing at various energy and humidity conditions (25 % and 100 % of normal landing energy (NLE); 2, 50 and 90 % relative humidity (RH)). Samples have been characterized using Temperature Programmed Reduction (TPR), Thermogravimetric Analysis coupled with Fourier Transform Infrared Spectroscopy (TGA/FTIR) and specific surface area (Brunauer-Einmet-Teller- BET) methods. The amount ofphysisorbed, chemisorbed and decomposed species strongly depends on the applied testing (brake dynamometer) conditions. Specific surface areas of debris obtained from different samples of materials are ranging from 800 to 1300 m2/g. TPR analysis indicates two reaction ranges, the first reaction range between 350 C and 600 C, and the second from 450 C to 800 C (maximum at 475 C and 680 C, respectively). CO2 and CO peaks detected using TGA/FTIR methods, occur as a result of decomposition of oxygen-containing functional groups that are formed by oxidation of the C/C during braking. The relative amount of these groups indicates the resistance of the brake materials to chemical reactivity.
Study of "adsorption/desorption" phenomena on friction debris of aircraft brakes
Studie über das 'Adsorption/Desorption'-Phänomen von Frikrionsrückständen bei Luftfahrzeugbremsen
2005
10 Seiten, 10 Bilder, 15 Quellen
Conference paper
English
Adsorption , BET-Methode , Bremse , chemische Reaktion , Desorption , Energie , Feuchtegehalt , flüchtiges Produkt , Fourier-Transform-Infrarotspektroskopie , Keramikverbundstoff , Kohlendioxid , Kohlenmonoxid , Kohlenstoff , Luftfahrzeug , Reibung , Rückstand , spezifische Oberfläche , Thermogravimetrie
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