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Influence of Carbon Nanotubes‐Based Coatings on the High‐Temperature Compression Strength of Al 2 O 3 ‐C Foam Filter Structures
Author(s) -
Ranglack-Klemm Yvonne,
Storti Enrico,
Aneziris Christos G.,
Biermann Horst
Publication year - 2020
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201900423
Subject(s) - materials science , composite material , scanning electron microscope , brittleness , carbon nanotube , compressive strength , compression (physics) , carbon nanofoam , porosity
Materials for steel‐melt filtration have to fulfill different thermomechanical requirements and especially withstand the thermal shock attack in the beginning of casting. In particular, carbon‐bonded alumina materials provide an excellent thermomechanical performance and have been used in functional components such as submerged entry nozzles, stoppers, and sliding gates for several years. The present study investigates the mechanical high‐temperature behavior of Al 2 O 3 ‐C foam filter structures with coatings based on carbon nanotubes+Al 2 O 3 ‐nanosheets (CNT‐ANS) and carbon nanotubes+Al 2 O 3 ‐nanospheres (CNT‐ANB) at 1100 and 1450 °C. The foam filters are tested in an electromechanical testing machine under argon atmosphere in quasi‐static compression. The tests show a brittle material behavior at 1100 °C with higher compressive strength of the coated filter samples. At 1450 °C, a loss of strength occurs, accompanied by an increase in plastic deformation. Rupture of struts and behavior of the coatings are microstructurally analyzed by scanning electron microscopy. As the mechanical load during the tests is much longer than in real immersion tests, the high‐temperature performance is considered trustworthy.