Filter materials have to fulfill different thermo-mechanical requirements and especially to withstand the thermal shock attack in the beginning of the steel melt casting. Carbon-bonded alumina materials provide an excellent thermo-mechanical performance and are since several years used in functional components such as submerged entry nozzles, stoppers and sliding gates. Emmel et al. found that the surface chemistry of the promising carbon-bonded alumina filters influences the trapping of non-metallic inclusions. They evaluated functionalized coatings of alumina, mullite and carbon-bonded magnesia on Al2O3-C filters in industrial trials. Apart from that, no studies were carried out regarding the high temperature behavior of these filter structures. The present investigations will deal with the high temperature mechanical behavior of Al2O3-C foam filter structures with functionalized coatings of Al2O3, Al2O3-C and Carbon Nanotubes (CNT) from 1100°C up to 1500°C. The foam filters were tested in an electro-mechanical testing machine under argon atmosphere in quasi-static compression tests and microstructural analyzes by scanning electron microscopy. The tests show that functionalized coatings preserve and in particular increase the strength and deformation behavior of the carbon bonded alumina filters. A maximum of strength was detected at temperatures of 1300 to 1400°C. Somehow, microstructural changes lead to variation in the compression behavior and will be explained in this paper.