INFINITE

NAnocomposite Core-Rim structures for Enhanced tOUghness and Strength at extreme temperatures

Principal Investigator: Luca Zoli
Involved Personnel: Diletta Sciti, Simone Failla, Antonio Vinci (1° anno), Francesca Servadei (1° anno), Bartolomeo Zanardi (2° anno), Cesare Melandri

Starting date: 18/07/2022
Duration: 36 month
Total funding: 452.492,00 $
Action: RMY RESEARCH OFFICE BROAD AGENCY ANNOUNCEMENT FOR FUNDAMENTAL RESEARCH W911NF-17-S-0002
CNR ISTEC Role: Coordinator
Coordinator: Luca Zoli(CNR-ISSMC)
Partnership: Missouri Science and Technology University (MS&T) – U.S.

Ultra-high temperature ceramic matrix composites (UHTCMCs) represent the next generation of reusable materials for applications exceeding 2000 °C under extreme environments such as aerospace, military, and nuclear sectors. These ideal materials are preferably composed of just two essential elements integrated optimally, such as a carbon fiber fabric and an ultra-high temperature ceramic matrix. The perfect composite requires no additional coatings before or after processing, and the interface between the matrix and the fibers must be weak enough to allow fiber pull-out to improve toughness, but also strong enough to prevent the penetration of corrosive or oxidizing gases during exposure. These materials are designed to be reusable through the in-situ formation of a protective scale during use.

To produce these revolutionary materials, a cost-effective and rapid process has been developed that involves the infiltration of powders into fiber fabrics, followed by sintering. The densification achieved through high-temperature sintering is a distinctive and crucial aspect of the process, as it imparts excellent mechanical properties and resistance to severe environments. However, uncontrolled densification can lead to undesirable brittleness.

The performance of these composites is influenced by various factors, including residual porosity and fiber/matrix interface reactions. The matrix must be dense enough to ensure oxidation resistance, but the interface must be controlled to avoid fiber degradation. Therefore, the type of interface that forms during sintering is of great importance.

The primary goal of this project is to study the densification behavior of UHTCMCs to maximize their high-temperature performance. The underlying hypothesis of the research is that liquid-phase sintering is more effective than solid-phase sintering for the densification of composites with carbon fibers, as it allows the fibers to remain intact.

A unidirectional carbon fiber structure is used, combined with a matrix primarily composed of zirconium diboride. The results of this research can then be extended to other matrices for UHTCMCs. Another important outcome of the project will be the creation of useful guidelines for the fabrication of advanced reusable materials for temperatures exceeding 2000°C, with a particular focus on aerospace applications.

The INFINITE project leverages the joint expertise of research groups from CNR-ISSMC in Faenza and Missouri Science and Technology (MS&T) to investigate the evolution of the matrix/fiber interface and its effects on mechanical performance at high temperatures.

Pubblications and patents

• Zoli L, Servadei F, Failla S, et al. ZrB₂–SiC ceramics toughened with oriented paper-derived graph-ite for a sustainable approach. Journal of Advanced Ceramics. 2024;13(2):207–219. https://doi.org/10.26599/JAC.2024.9220842

Conferences or events

• 47° International Conference and Expo on Advanced Ceramics and Composites (ICACC2023), Daytona, USA, 22-27 gennaio 2023.
• 11° International Conference of high temperature on Ceramic Matrix Composites (HT-CMC 11), 27-31 August 2023, Jeju, Corea.
• ECI conference (Ultra-High Temperature Ceramics: Materials for Extreme Environment Applications VI), 14-19 April 2024 Giardini Naxos, Messina, Sicilia, Italy.
• 74° International Astronautical Congress – IAC, 02 – 06 October 2023, Baku, Azerbaijan.
• 10° International Ceramic Congress (ICC’10), 14-18 july 2024, Montreal, Canada.
• Part of Italian Delegation at Texas A&M University (TAMU), John Hopkins University (JHU) and Italian ambassy at Washinton from 18 to 24 July 2024.

Awards

• best poster “ZrB₂-SiC ceramics toughened with oriented paper-derived graphite for a sustainable approach” a conferenza ECI (Ultra-High Temperature Ceramics: Materials for Extreme Environment Applications VI), April 14 – 19, 2024 Giardini Naxos, Messina, Sicilia, Italia.
• JECS Trust 2024 “Thermo-mechanical behavior of liquid phase sintered carbon fiber reinforced UHTC composites” awarded the training of a young researcher at Missouri University, Rolla US (Prof.  William G. Fahrenholtz team).