Advanced Ceramics Applications

MATECH Ultra-High-Temperature (UHT) Oxide Fibers for CMCs.   MATECH has developed the world’s first ultra-high-temperature (UHT) oxide structural ceramic fiber, known as Refractory-Alloyed Yttrium Aluminum Garnet (RAYAG). With this innovation, oxide/oxide (Ox/Ox) ceramic matrix composites (CMCs) can challenge the decades long dominance of non-oxide CMCs in high temperature (HT) and UHT applications. MATECH’s breakthrough enables Ox/Ox CMCs to compete in the demanding applications of high temperature turbines for commercial and military propulsion, non-ablative heat shields, and hypersonic aeroshells. MATECH’s new oxide fiber retains significant strength up to 1600C!   Perhaps the most recognized state-of-the-art (SOTA) oxide fibers commercially available are the Nextel family of oxide ceramic fibers, manufactured by 3M corporation for over 30 years. These sol-gel derived ceramic fibers have allowed Ox/Ox CMCs to perform numerous moderately high temperature roles. Unfortunately, oxide CMCs haven’t been able to compete with the higher temperature capabilities of non-oxide CMCs, such as C/C, C/SiC, and SiC/SiC, as prime examples. They do have, however, long-term stability in oxidizing environments. For the first time, due to this unprecedented innovation, almost indefinite stability at extremely high temperatures can now be achieved in one composite system, RAYAG/RAYAG CMCs.   MATECH developed high ceramic yield dry spinning chemistries to fabricate high yttrium aluminum garnet (YAG) and Refractory Alloyed YAG (RAYAG) structural ceramic fibers and matrices. Refractory Alloyed YAG contains a significant fraction of an ultra-high-temperature refractory metal oxide in a YAG matrix. Dense fibers of both compositions have been demonstrated (Figure 1). Significant high strength retention is observed in RAYAG when compared to state-of-the-art commercial oxide ceramic fibers (see Figure 2). Because they are oxides, unlike SiC fibers, they are not nearly as susceptible to moisture and oxidation-related degradation.  Polymers for YAG and RAYAG matrices have also been developed, thereby eliminating any coefficient of thermal expansion (CTE) mismatch between fibers and matrices in Ox/Ox CMC manufacturing.    Photoluminescence and Thermoluminescence in these systems have been observed when doped with various lanthanide elements, see Figure 2 below for europium-doped YAG fibers. Thermoluminescence would dissipate heat generated during hypersonic flight for TPS and leading-edge applications.   MATECH’s development of RAYAG ceramic fibers and RAYAG/RAYAG CMCs can usher in a new era of ultra-high-temperature oxide CMCs that are sorely needed for such demanding applications as high temperature turbines for commercial and military propulsion, non-ablative heat shields, and hypersonic aeroshells.

🚀 Exciting News from NC State! Our research team has developed a groundbreaking laser technique to create ultra-high temperature ceramics, such as hafnium carbide (HfC), more efficiently and with less energy. This innovation has significant impacts for industries requiring materials that can withstand extreme heat, such as aerospace and nuclear energy. Traditional methods involve heating materials in furnaces at temperatures above 2,200°C, which is time-consuming and energy-intensive. Our new approach uses a 120-watt laser to sinter a liquid polymer precursor in an inert environment, transforming it into solid ceramic without the need for such extreme conditions. This technique offers two main applications: 1. Coating: Applying ultra-high temperature ceramic coatings to materials like carbon composites. 2. 3D Printing: Creating complex ceramic structures layer by layer, enabling more versatile and precise manufacturing. This advancement not only streamlines the production process but also opens new possibilities for designing components that can endure extreme environments. For more details, read the full article here: https://lnkd.in/eE2Wh2TR #Innovation #MaterialsScience #NCStateResearch #AdvancedManufacturing

Oxide Ceramics: Alumina (Al2O3) stands out as a fundamental compound in "Technical Ceramics" due to its exceptional versatility. It finds applications in various fields such as abrasion resistance, cutting, friction reduction, wear resistance, refractory uses, electricity, electronics, optics, biomedical applications, and even jewelry manufacturing. Silica (SiO2) is another essential compound for both ceramists and glassmakers. The alumina-silica diagram holds significant importance for ceramists, akin to the iron-carbon diagram for metallurgists. Magnesia (MgO) and spinel (MgAl2O4) play crucial roles as refractory materials in the iron and steel industry. Zirconia (ZrO2), distinct from zirconium silicate (zircon, ZrSiO4), finds utility in ceramic colors, ionic conduction, mechanical applications, and jewelry crafting. Uranium oxide (UO2) serves as the primary component in nuclear fuels, sometimes blended with a small amount of Plutonium oxide (PuO2) to form "mixed oxide nuclear fuels" (MOXs). Barium Titanate (BaTiO3) acts as a dielectric or semiconductor based on its doping and stoichiometry. It serves as a foundational material in ceramic capacitors manufacturing and is integral to producing various probes and sensors. Soft ferrites and hard ferrites, including hexaferrites, play essential roles in magnetic applications. Soft ferrites with a spinel structure, while hard hexaferrites feature a hexagonal structure. Numerous metallic oxides find applications in ceramics, including Yttrium Oxide (Y2O3), Beryllium Oxide (BeO), Zinc Oxide (ZnO), Tin Oxide (SnO2), superconductive cuprates like YBa2Cu3O7. #OxideCeramics #Ceramic #Ceramics #MaterialScience #Alumina #Silica #Ferrite #Zirconia #Magnesia #BariumTitanate #ZincOxide #TinOxide #CeramicScience #CeramicEngineering #CeramicTech #PhaseDiagram #CeramicTechnology #InorganicChemistry https://lnkd.in/g_wQHdim Alumina - Silica Phase Diagram: