Enhanced flexibility and thermal conductivity of HfC decorated carbon nanofiber mats. (5th March 2023)

• Record Type: Journal Article
• Authors: Nisar, Ambreen; Lou, Lihua; Boesl, Benjamin; Agarwal, Arvind
• Is Part Of: Carbon. Volume 205(2023)
• Page Start: 573
• Page End: 582
• Publication Date: 2023-03-05
• Subjects: Carbon nanofibers (Cnf) -- Electrospinning -- Hafnium carbide (HfC) -- Spark plasma sintering (SPS) -- Layered structure; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2023.01.055
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Future-generation spacecraft components allude discovery of novel materials that can withstand extreme environments (>2000 °C). The combined effect of ultra-high temperature ceramics (UHTCs) and carbon fibers (Cf ) can satisfy the demanding requirements of aerospace applications. A novel, hybrid, and flexible hafnium carbide (HfC)-decorated carbon nanofiber (C nf ) mat was fabricated via electrospinning. Enhanced thermal stability of the flexible HfC decorated Cnf over Cnf can be elucidated from the 20-fold increment in thermal conductivity and the onset of degradation at higher temperatures (840 °C). Successful integration of multi-layered sandwich lattice using in-housed fabricated HfC decorated Cnf showed retention of the fibrous structure even after extreme spark plasma sintering (SPS) process at 1850 °C. Fabricating a similar multi-layered structure using procured Cf was unsuccessful due to bundled agglomeration and micron-sized fibers. High-load indentation suggests that HfC decorated Cnf interlayer is stronger (∼2.3 times) than the parent UHTC with no cracking at the interface. Compared with the HfC matrix, the indentation-damaged area at the interface reduced up to ∼56% due to toughening mechanisms such as Cnf, fiber pull-out and bridging. The synthesized HfC decorated Cnf mat is proposed as an ultra-thin filler material for joining similar or dissimilar UHTCs while maintaining similar chemistry and better mechanical integrity at the interface. The findings insinuate a new paradigm in designing hybrid and flexible ceramic-containing materials for thermal protection systems (TPS) of future-generation spacecraft components that can mitigate failure in extreme environments (>2000 °C). Graphical abstract: Image 1