Ceramic Matrix Composites: Session II
Sponsored by: ACerS Engineering Ceramics Division
Program Organizers: Narottam Bansal, NASA Glenn Research Center; Jacques Lamon, CNRS; Sung Choi, Naval Air Systems Command

Monday 2:00 PM
October 18, 2021
Room: B232
Location: Greater Columbus Convention Center

2:00 PM  Invited
Ceramic Matrix Composite Technologies for Accident-tolerant Fuel Applications – Progress and Opportunities: Yutai Katoh¹; Takaaki Koyanagi¹; David Arregui-Mena¹; Peter Mouche¹; Ken Kane¹; Peng Xu²; Christian Deck³; ¹Oak Ridge National Laboratory; ²Idaho National Laboratory; ³General Atomics
     Nuclear energy continues being an important baseline electricity source with the minimal carbon footprint. In pursuit of inherently safe and economical nuclear energy, development of SiC-based ceramic matrix composite materials continues as the enabling technology for accident-tolerant fuels and core structures for the current fleet and future reactors. The recent research and development focuses include the mechanisms of and mitigation for potential hermeticity compromise, oxidation and environmentally assisted failure in the severe accident conditions, integrated in-pile testing of surrogate and fueled rodlets, and the other technical basis toward the lead test rod program. This paper overviews the recent development of materials and technologies and discusses the needs and opportunities for materials science and engineering research.This study was supported by the US Department Energy, Office of Nuclear Energy, Accident Tolerant Fuels program and Westinghouse Electric Corporation/General Atomics FOA program under contact DE-AC05-00OR22725 with ORNL, managed by UT Battelle, LLC.

2:40 PM
Synergistic Effects of Oxidation and Applied Load on SiC/BN/SiC Ceramic Matrix Composite Durability at Intermediate Temperatures: Kaitlin Detwiler¹; Marcus Dozer¹; Elizabeth Opila¹; ¹University of Virginia
    SiC/BN/SiC ceramic matrix composites (CMCs) are currently in service as hot section aeroturbine engine components. Despite their current use, CMC life prediction models that account for combined applied load and oxidation lag in development. This work aims to provide data for validation and improvement of these models. SiC/BN/SiC CMCs were oxidized in dry oxygen and 50% H2O/oxygen at intermediate temperatures between 400 and 800C to establish baseline oxidation behavior in the absence of load. The CMCs were then exposed in similar intermediate temperature oxidizing environments at three different tensile loads: first matrix cracking, increased crack densities, and loads above the proportional limit. Specimens were exposed for times up to 100h in load-hold experiments and then characterized by scanning electron microscopy and energy dispersive spectroscopy, with statistical analysis of observed damage. Synergies between oxidation/applied load were explored.

3:20 PM
Oxidation of BN Coatings in SiC/SiC Composites: Victoria Christensen¹; Frank Zok¹; ¹University of California, Santa Barbara
    Ceramic composites based on BN-coated SiC fibers and SiC matrices often exhibit property degradation at intermediate temperatures (600蚓-1000蚓). While it has been established that the degradation involves oxidation of the BN coatings, the mechanisms remain poorly understood. To address this challenge, oxidation experiments were performed on SiC/BN/SiC minicomposites in dry and wet air. Transverse and longitudinal sections through the oxidized specimens were characterized using scanning and transmission electron microscopy and x-ray dispersive spectroscopy. Complementary thermogravimetric analyses were performed on bare and coated fibers. The experimental results coupled with models of thermochemistry provide a means for understanding the time scales and environmental regimes over which the degradation mechanisms operate.

3:40 PM Break

4:00 PM  Cancelled
Development of Low Temperature, Dense Nano-composite Material Combining Electrophoretic and Atomic Layer Deposition Technique: Sumit Bhattacharya¹; Michael Pellin¹; Abdellatif Yacout¹; ¹Argonne National Laboratory
    We are reporting the development of ceramic matrix composites (CMC's) (e.g., a ceramic/ceramic, metal/ceramic) which is produced at temperatures below 150 慢 with capabilities of forming composites via infiltration of a porous structure (e.g., wrapped ceramic fiber, metal foam) and through direct deposition on a substrate (e.g., metal, or ceramic base). Compared to conventional techniques for CMCs manufacturing the composite material achieves a dense microstructure without application of a mandatory sintering step. This method produces a composite which is homogeneous in composition and without open porosities. This process can also be easily applied as a hard barrier coating over metal substrates without exposing the base material to extreme conditions of high temperatures and harsh chemicals. This presentation discusses the mechanical and physical properties of our developed composite material.

4:20 PM
High Temperature Composites Based on Zirconia Cement. High Temperature Composites Based on Ceramic Cements.: Nickolai Iliukha¹; ¹Kyiv University
     High temperature composite based on ceramic cements. New cements contains double oxides and aluminates of calcium, barium, strontium. The date obtained allow to classify new cements as high-property: fire-proof, quick-hardening and high-strength binders. The synthesis of cement clinker takes place through solid phase reactions. The newer developed cements of the highest fire resistance show only insignificant loss of strength when being heated, which can be accounted for by formation of high temperature-proof contacts between the new hydrate formations and double oxides grains.The development of new high temperature composites based on zirconium cements for the application in various consuming industries has been illustrated and is well documented in terms of performance improvements. They are meant to protect units from influence of temperature more than 2073 K. They are used for coating of high temperature head treatment, coating of fuel - construction, in coating of furnace for making fuel, carbon-reactor, H2-Furnace.