Results 161 to 170 of about 549 (213)

CIRA activities on UHTC's: on-ground and in flight experimentations

17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference, 2011
CIRA has been working since almost a decade on the possibility to use a new class of ceramic materials, the so called Ultra High Temperature Ceramics (UHTC’s), for space applications, and specifically for some critical parts of thermal protection systems.It is well known that sharp aerodynamic configurations could provide much more efficiency in ...
Roberto Gardi, Antonio Del Vecchio, Giuliano Marino, Gennaro Russo   +3 more
openaire   +1 more source

Electronic Structure and Mechanical Properties of NiB: A Promising Interphase Material for Future UHTC _f /UHTC Composites

Journal of the American Ceramic Society, 2016
Weak interphases play a pivotal role by acting as mechanical fuse to deflect matrix cracks in future ultrahigh‐temperature ceramic fiber reinforced ceramic matrix ( UHTC f / UHTC ) composites.
Yanchun Zhou, Huimin Xiang, Zhihai Feng, Zhongping Li   +3 more
openaire   +1 more source

Ablation behavior of UHTCs carbide-modified C/C composites in extreme aerobic environments (3000℃): Evolution mechanisms of oxides film structure

Corrosion Science
To mitigate ablation loss in carbon/carbon (C/C) composites under extreme thermal conditions (>3000℃), a novel analytical framework of “extreme environment - microstructure evolution - ablation resistance” was developed via two-way coupled simulation and
Menglin Zhang, Dou Hu
exaly   +2 more sources

Pressureless sintering of Ta0.8Hf0.2C UHTC in the presence of MoSi2

Ceramics International, 2013
Abstract Ta0.8Hf0.2C ceramic has the highest melting point among the known materials (4000 °C). However, this high melting point makes the ceramic difficult to be sintered at temperatures lower than 2300 °C, pressurelessly. The purpose of this study is to consolidate Ta0.8Hf0.2C UHTC by pressureless sintering at 2000 °C using MoSi2 as sintering aid.
S.A. Ghaffari, M.A. Faghihi-Sani, F. Golestani-Fard, S. Ebrahimi   +3 more
openaire   +1 more source

Production of UHTC Complex Shapes and Architectures

2013
In spite of the difficult sinterability of Zr and Hf borides and carbides, recent results highlight that these ceramics can be produced with full density, fine microstructure, and controlled mechanical and thermal properties, through different procedures: pressureless sintering and hot pressing with proper sintering aids, reactive synthesis/sintering ...
Valentina Medri, Diletta Sciti, Elena Landi   +2 more
openaire   +2 more sources

TEM study on UHTCs and composites

2016
Research on UHTCs has generally involved two major fields: the improvement of mechanical properties and the oxidation resistance. High performances are achieved upon careful tailoring of the microstructure, obtained through an aware control of the sintering additives, secondary phases and densification process.
Laura Silvestroni, Diletta Sciti, Stefan Lauterbach, HansJoachim Kleebe   +3 more
openaire   +4 more sources

Production and characterization of toughened UHTC

2011
Ultra-high temperature ceramics are material candidate for application in aggressive environment, especially in sharp components of future generation of space vehicles, driven by the ultimate goal of major speed with new propulsion and hypersonic models.
Silvestroni, Laura, Dalle Fabbriche, Daniele, Melandri, Cesare, Guicciardi, Stefano, Sciti, Diletta   +4 more
openaire   +1 more source

Aerothermodynamic study of UHTC-based thermal protection systems

Aerospace Science and Technology, 2005
Abstract Computational Fluid Dynamics (CFD) simulations are coupled to a thermal analysis model to investigate the thermal response of the new Ultra High Temperature Ceramics (UHTC) being considered for Thermal Protection Systems (TPS) of future reusable re-entry vehicles.
SAVINO, RAFFAELE, DE STEFANO FUMO M., PATERNA D., SERPICO M.   +3 more
openaire   +2 more sources

First principle study of UHTC ternary diboride, Cr2AlB2

AIP Conference Proceedings, 2018
In this paper ab-initio study of the structural, electronic and optical properties of ternary metal boride Cr2AlB2 using full potential linear augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). The study of structural properties shows that Cr2AlB2 is metallic in nature and have orthorhombic crystal structure.
Anugya Rastogi, Priyanka Rajpoot, U. P. Verma   +2 more
openaire   +1 more source

Processing and sintering of fiber-containing UHTCs

2014
Ultra high temperature ceramics (UHTC) include borides and carbides of early transition metals and are presently considered a class of promising materials for several applications, the most appealing ones being in the aerospace and energy sectors. Crucial issues for application in severe environment is the improvement of fracture toughness and thermal ...
D. Sciti, L. Silvestroni, L. Zoli, V. Medri   +3 more
openaire   +1 more source