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Oxide Ceramic matrix composites (Ox-CMCs) combine excellent strength, chemical resistance, and thermal stability. These qualities make them suitable for components exposed to harsh and oxidative environments, such as gas turbine engines and thermal protection systems.

However, maintaining these properties at high temperatures is challenging due to grain coarsening and degradation above 1000°C. A recent study, “Enhancing Thermal Stability of Oxide Ceramic Matrix Composites via Matrix Doping,” investigated strategies to address these issues.

Baikowski® contributed to the study with its high-purity alumina BA15 powder, which was selected for its particle size distribution (d₅₀ = 120 nm) and exceptional chemical purity. These attributes ensured a consistent and reliable matrix material, critical for evaluating the effects of doping. For that, water-based ceramic suspensions containing a solid content of 50 vol% were prepared.

For more information, explore our range of products for CMCs , including BA15 powder and our latest innovation, SLAZ, a high-purity alumina slurry doped with Mathym’s zilight® nano-zirconia.

Materials and Methods

Composites reinforced with Nextel 610 fibers and alumina matrices were produced in two variations: one using non-doped alumina and the other doped with 480 ppm MgO.

MgO was chosen due to its recognized ability to inhibit grain boundary mobility and reduce grain growth, making it an effective doping agent for enhancing thermal stability.

Fabricated through an ionotropic gelation technique, the composites were sintered at 1200°C, followed by heat treatments at 1300°C and 1400°C. SEM, WDX, and tensile strength tests were conducted to assess the microstructural and mechanical impacts of doping.

CMC Performance With Baikowski’s Doped Alumina

Microstructural Findings:

• Both doped and non-doped composites had similar initial microstructures with uniform equiaxial grains.
• Thermal exposure induced grain growth in both samples, but MgO-doped composites showed smaller, more refined grains and significantly fewer abnormal grains, especially near the fiber regions.

Elemental Interactions:

• WDX analysis showed that silicon (Si), which is part of the Nextel 610 fibers, diffuses outward toward the matrix after heat exposure, while magnesium (Mg) from the matrix diffuses slightly into the fibers.This interaction helped suppress excessive grain coarsening in MgO-doped composites, leading to narrower fiber grain size distributions and smaller grains compared to non-doped samples, resulting in the reduction of strength loss after heat treatments.

Mechanical Performance:

• Both types of composites had comparable tensile strength (~135 MPa) in the as-processed state.
• Post-heat treatment, MgO-doped composites retained higher tensile strength, with reductions of 8% at 1300°C and 41% at 1400°C, compared to 27% and 62% reductions for non-doped samples.

The study highlights the benefits of matrix doping for thermal stability enhancement of Ox-CMCs, particularly when using high-purity, MgO-doped alumina from Baikowski®. The customized alumina matrix effectively reduced fiber grain growth and preserved mechanical properties under high-temperature conditions.

Baikowski®’s ability to deliver tailored solutions through strong R&D capabilities and close collaboration with industry ensures its alumina powders meet stringent application demands. These advancements further position Baikowski® as a trusted partner in developing high-performance materials for the aerospace sector and other high-temperature applications.

Learn more by downloading our dedicated White Paper👇

Advanced Materials for oxide CMCs
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This article summarizes the study “Transparent Alumina Ceramics Fabricated by 3D Printing and Vacuum Sintering”, which explored the potential of additive manufacturing to revolutionize ceramic fabrication.

The research demonstrated that combining 3D printing with high-performance materials like Baikalox® CR10 alumina powder, enhanced with MgO doping, could rival traditional manufacturing methods in terms of quality while introducing unprecedented design flexibility.

Since the study’s completion in 2020, advancements in 3D printing technology have continued to push boundaries, offering even greater precision, scalability, and potential applications.

The Goal: Pioneering 3D Printing for Transparent Ceramics

Transparent ceramics have long been valued for their exceptional mechanical, thermal, and optical properties, with applications spanning aerospace, defense, optics, and electronics. However, traditional fabrication methods, such as cold isostatic pressing (CIP) and vacuum sintering, often require extensive tooling and are limited in producing complex geometries.

This study aimed at addressing these limitations by leveraging extrusion-based 3D printing to fabricate high-density transparent ceramics, exploring the use of two-step vacuum sintering to optimize optical and mechanical performance.

The goal was to evaluate whether 3D printing could deliver results comparable to CIP while enabling greater design flexibility.

The Process: From Powder to Transparency

The fabrication process involved several key steps, each optimized to achieve near-perfect transparency in the final ceramics.

Baikowski Powder Properties

Baikalox® CR10D alumina powder, enhanced with 625 ppm MgO doping, a composition specifically tailored for superior sintering performance, was used in this study. This high-purity alumina features a controlled submicron particle size (D50: 0.731 µm) and a narrow particle size distribution, making it ideal for achieving high-density ceramics. The addition of MgO acted as a sintering aid, effectively promoting densification and enhancing grain boundary control during the vacuum sintering process.

The specific surface area (SSA) of the powder, measured using the BET method, was 7.9571 ± 0.1174 m²/g.Its submicron size, high surface area, and nearly spherical morphology ensure excellent packing efficiency and optimal densification behavior, critical factors for producing transparent ceramics with superior optical and mechanical properties.

Learn more about Baikalox® CR range

Slurry Formulation

To prepare the ceramic slurry for 3D printing, Baikalox® CR10D powder was combined with water and a small percentage of ISOBAM™, which served as both a binder and dispersant to achieve the desired viscosity.The optimal formulation—72 wt% alumina and 0.7 wt% ISOBAM™—struck the perfect balance between viscosity and printability.

This carefully optimized slurry exhibited shear-thinning behavior, allowing for smooth and precise extrusion through the printer nozzle while ensuring structural stability during and after printing.

3D Printing Technology and Post-Processing

The slurry was loaded into an extrusion-based 3D printer, allowing the creation of complex shapes layer by layer. The printed parts were then dried, debinded, and sintered using a two-step vacuum sintering process. This approach minimized grain growth while achieving near full density (>99%).

Final polishing enhanced the transparency, resulting in ceramics with a total transmittance of up to 70% at 800 nm.

Key Insights and Applications of 3D-Printed Ceramics with Baikalox® Alumina

Several benefits in terms of capabilities of 3D printing for transparent ceramics were revealed by the study:

• Performance Equivalence
  The study demonstrated that 3D-printed ceramics using Baikowski®’s CR10D alumina powder achieved over 99% relative density and similar transmittance levels (70% at 800 nm) to CIP-processed ceramics, reinforcing the reliability of additive manufacturing for optical-quality applications.
• Innovation in Geometry
  Unlike usual methods, 3D printing allowed for the creation of complex shapes without compromising quality, showcasing its advantage for customized and intricate designs.
• Optimized Processes
  Two-step vacuum sintering enhanced transparency by reducing grain size compared to single-step sintering, underscoring the benefits of process optimization.
• Technology Evolution
  While this study represents the state of technology in 2020, 3D printing has since improved in resolution, materials, and scalability, further expanding its potential for intricate geometries in high-performance applications.

For additional details, explore the full study here

These results could have implications for various industries. Transparent ceramics are critical in optical lenses, protective windows, and laser systems. The design of custom geometries enables the creation of advanced optical components, improving performance and reducing manufacturing costs.

As technology continues to evolve, its potential for intricate geometries and miniaturized components expands the horizon for applications in photonics, sensors and more.

This study reinforces Baikowski®’s commitment to driving innovation through high-quality materials. The use of Baikalox® CR10D powder highlights the critical role of advanced materials in enabling the success of such cutting-edge technologies.

Learn more with our white paper dedicated to Ceramic 3D printing powders and slurries.

Ceramic Matrix Composites (CMCs) represent a pivotal advancement in materials science, uniquely addressing contemporary and future challenges across diverse applications. These materials leverage the inherent benefits of ceramics—high thermal stability, corrosion resistance, and excellent mechanical properties—while overcoming their brittleness through composite engineering.

Their innovative use spans sectors from aerospace, where their lightweight, thermal resistance, and mechanical strength are critical for efficiency and durability in extreme environments, to medicine, energy, and electronics, making them indispensable solutions for today’s most demanding technological environments.

Advancements in CMC processing are critical to unlocking their potential. Techniques like additive manufacturing, flash sintering, and high-pressure sintering allow for complex shapes, efficient resource use, and minimized waste. Furthermore, innovations in nanostructured materials and bio-inspired designs drive both performance improvements and ecological benefits.

SLAz: The Key to Next-Generation Ceramic Matrix Composites

The SLAz slurry range, a synergistic blend of our renowned Baikalox® High Purity Alumina & cutting-edge zilight® nano-zirconia delivers a unique combination of properties tailored to meet the high-performance demands of Ceramic Matrix Composites (CMCs).

In fact, SLAz offers key advantages in CMC manufacturing  such as:

• Uniform Dispersion: Featuring Mathym®’s expertly dispersed nano-zirconia, SLAz ensures a consistent and homogenous distribution within the alumina matrix for dependable results.
• Enhanced Stability: Withstanding a broad pH spectrum from 4 to 10, SLAz delivers stability you can count on in various operating environments.
• Optimized Viscosity: Engineered for suiting your process, SLAz maintains low viscosity without compromising quality, even with the inclusion of nano-zirconia.

SLAz also shows great promise in advancing coating and 3D printing technologies. Explore its potential today!

SLAz SLURRIES
for CMC applications

Download the SLAz leaflet

As the global demand for effective water treatment systems grows, particularly in regions where access to clean drinking water is scarce, the development of innovative filtration technologies has become a focus.

In a recent study titled “Removal of MS2 and fr Bacteriophages Using MgAl₂O₄-Modified, Al₂O₃-Stabilized Porous Ceramic Granules for Drinking Water Treatment”, researchers investigated the effectiveness of an advanced composite-based filtration membrane.

This ceramic membrane, made from alumina (Al₂O₃) and Baikowski® magnesium aluminate spinel (MgAl₂O₄), demonstrates potential for removing viruses, such as bacteriophages and other microorganisms that contribute to waterborne diseases.

Combatting Waterbone Pathogens with Spinel-based Composite Membranes

The membrane is fabricated by integrating spinel granules into an alumina matrix. This composite approach leverages the mechanical strength of alumina, and the filtration capabilities of spinel due to its fine pore structure and stability.

The Baikowski® product used S25CR is a high-purity jet-milled spinel powder (dv50 = 0.25 µm and surface area of 21–24 m²/g).

This combination of materials allows the membrane to maintain its performance even in extreme environmental conditions.

Baikowski® Spinel Powder Benefits for advanced filtration applications

At Baikowski®, spinel powders are designed to achieve the highest standards in ceramic applications. Here’s how our S25CR product align with the demand of advanced filtration systems:

• Particle Size and size distribution: Our jet-milled spinel powder offer fine particle size and controlled particle size distribution around 0.25 µm that enable precise tailoring of membrane porosity.
• High Purity Levels: With over 99% phase purity, our spinel powder minimizes impurities that can interfere with membrane performance. This purity is essential in preventing contamination, which can degrade the efficacy of filtration in sensitive applications like water filtration.

Post-Filtration Characterization and Thermal Regeneration

A critical part of the study involved characterizing the materials after filtration to assess the durability and stability of the membrane. X-ray diffraction analysis confirmed that the phase composition of the spinel granules was preserved after exposure to 2 liters of contaminated water, indicating the membrane’s robustness. Electron microscopy further demonstrated that the granular structure remained intact, ensuring the membrane’s continued effectiveness even after prolonged use.

Additionally, the study measured the release of aluminum and magnesium into the permeate after filtration. No aluminum was detected, and the magnesium levels were significantly below the WHO’s recommended threshold for drinking water. This low level of magnesium release is a notable benefit, as excessive magnesium in water contributes to hardness.

One of the standout features of the spinel-based filtration system is its potential for thermal regeneration. When the membrane’s pores become clogged with contaminants, heat treatment at 400°C can restore its filtration capacity. This ability to regenerate the membrane extends its lifespan and makes it a more sustainable solution for water treatment.

Product Customization

In conclusion, spinel-based composite membranes offer a solution for filtering viruses and other microorganisms from drinking water, with the added benefit of being durable and regenerable. The Baikowski®’s high-purity spinel powder, S25CR, play a role in these advanced filtration technologies, ensuring both high filtration efficiency and long-term stability.
For more detailed insights, you can explore the full study here.

At Baikowski®, our R&D teams customize solutions, such as adjusting the dopant or the particle size, to meet your specifications. We work closely together to develop products that push the boundaries of your application needs. Any questions? Contact-us

The search for dental restorative materials that seamlessly blend strength, safety, and aesthetic appeal has long been a priority in dentistry. Mathym®’s innovative nano-zirconia suspension with high refractive index, zilight®, is at the forefront of addressing this challenge.

Meeting the Demand for Aesthetic and Strong Dental Materials

Patients are looking for dental restorations that are not only durable but also visually natural. Traditional materials like porcelain-fused-to-metal often fall short, especially in visible areas like the front teeth due to their opacity and sometimes greyish hue. While all-ceramic restorations offer some improvements, they still face some issues such as chipping, brittleness, and in particular limited translucency.

Yttria-Stabilized Zirconia (YSZ) ceramics, particularly those doped with 3 mol.% yttria (3YSZ), have gained popularity for their high strength, biocompatibility, and compatibility with CAD-CAM technologies. However, conventional 3YSZ often lacks the translucency required for highly aesthetic dental restorations.

Achieving Superior Optical and Mechanical Properties with zilight® range

The control of Mathym’s zirconia grain size to less than 100 nm enables to produce high translucency ceramics without compromising solidity. Moreover, the adjustment of yttria doping in the 8 mol.% range also allows enhanced optical transparency. The obtained ceramics exhibit opalescence similar to natural enamel, creating a bluish and orange appearance under different lighting conditions.

These properties linked to the miniaturization of residual pores, the refinement of grain size, proper doping concentration, and sintering ability at only 900°C make zilight® a superior alternative to existing commercial options for dental applications.

The low sintering temperature is a remarkable competitive benefit that also allows energy consumption reduction, short processing times, and can minimize potential thermal damage to other components.

Compatible with ceramic 3D printing, our innovative solution is designed to meet advanced restoration techniques needs.

Enhancing Dental Applications with Mathym’s Innovations

Mathym’s commitment to innovation extends beyond zilight® nano-zirconia suspension.

Our offering also includes advanced dental nanofillers such as ytterbium fluoride, filixio®, and cerium nanoparticles, designed to enhance or add specific properties to dental materials such as radiopacity, wear resistance and color stability.

Aditionally, the nanoparticle functionalization ensures compatibility with various dental monomers, even at high concentrations.

All these advancements bring superior results across a variety of restorative procedures while preventing secondary caries by inhibiting bacterial growth and promoting enamel remineralization.

Learn more about Mathym’s dental offering

For further details and tailored solutions, contact our teams to discuss your needs.

Baikowski is at the forefront of innovation in materials science. Our products enable research and technological advancements in the field of technicl ceramics. Among the applications, there is the development of graphene oxide (GO) composite membranes anchored on α-alumina substrates as mentioned in the following scientific publication « Composite GO/Ceramic Membranes Prepared via Chemical Attachment: Characterisation and Gas Permeance Properties. »

By providing a stable and inert platform for GO deposition, the substrates enable the creation of composite membranes with finely tuned pore structures and enhanced separation capabilities in this study, essential for industrial applications.

The porous ceramic substrates made with our High Purity CR6 Baikalox® powder, provide the necessary resistance in high-temperature and corrosive environments where polymeric membranes will fail.

Potential Applications of Composite GO/ceramic membranes

These membranes exhibits enhanced stability and permeance, as well as tailored surface properties that can be employed in various industries to address critical separation and filtration challenges such as :

• 🌟 Gas Separation: The composite membranes are suitable for applications in industrial gas separation processes, purification of natural gas, and carbon capture technologies thanks to their ability to selectively permeate certain gases while retaining others.
• 🌟 Water Treatment: The hydrophilic and hydrophobic modifications enabled by chemical linkers such as PDA, GPTMS, and APTMS allow the membranes to effectively separate contaminants from water. This application is particularly relevant for wastewater treatment, desalination, and the removal of organic and inorganic pollutants from water sources.
• 🌟 Chemical Processing: The composite membranes’ resistance to chemical products and thermal stability make them suitable for the separation of organic solvents, recovery of valuable chemicals, and purification of reaction products.
• 🌟 Energy Sector: The selective permeation properties can be harnessed to separate hydrogen from other gases, which is a critical step in producing high-purity hydrogen for fuel cells and other energy applications.
• 🌟 Environmental Protection: By enabling the effective separation of harmful gases and pollutants, these membranes can help reduce emissions and treat industrial effluents, supporting cleaner and more sustainable processes.

CR6 High-Purity α-Alumina Powder Benefits

CR6 is a  powder of our Baikalox® range of products, well known for its fine particle size and excellent sintering properties.

These characteristics make it an ideal material for creating dense and robust ceramic supports, which are essential for high-performance composite membranes.

The specific properties of CR6 in that application include:

• 🌟 High Purity: this characteristic ensures minimal contamination, which is crucial for maintaining the integrity of the ceramic substrates and the GO layer deposited on them.
• 🌟 Controlled Particle Size Distribution: It contributes to the creation of uniform macroporous structures. This uniformity is essential for consistent membrane performance, as it influences both gas and water permeance.
• 🌟 Chemical Compatibility: compatibility of CR6 with various chemical linkers, such as polydopamine (PDA), 3-Glycidoxypropyltrimethoxysilane (GPTMS), and 3-Aminopropyltrimethoxysilane (APTMS), facilitated the effective anchoring of GO layers onto the ceramic substrates.
• 🌟 Excellent Sintering Behavior: It allows the creation of mechanically strong and thermally stable supports.

In the referenced study, custom-made α-alumina disks with a ~2 mm thickness and a 22 mm diameter were employed as substrates. The disks were fabricated by pressing the CR6 alumina powder in a custom-made mold and sintering at 800°C for 30 hours and further at 1180°C for 2 hours. One side of the disk was polished until no obvious scratch was observed under visual inspection with a light microscope.

How CR6 Alumina Contributes to Membrane Performance?

One of the primary challenges in composite membrane technology is ensuring strong and stable adhesion of GO layers to ceramic substrates.
The success here is mainly due to :

• 🌟 Enhanced Stability: The CR6-based substrates have showed remarkable stability, maintaining their structural integrity and performance under various conditions.
• 🌟 The smooth and polished surface: these surface characteristics have ensured optimal interaction with the modifying agents (PDA, APTES, GLYMO) and the graphene-based nanocomposites.
• 🌟 Thickness: The substrates have enabled the formation of composite membranes with precise thickness control, optimizing the membrane for different separation applications.

Our high purity CR6 alumina has proven to be a critical component in the advancement of composite membrane technologies. Its superior properties facilitate the creation of reliable and high-performing membrane supports, enabling the successful integration of graphene-based nanocomposites.

This synergy between high-purity alumina and advanced nanomaterials opens new possibilities for applications in gas separation, water purification, and other fields requiring durable and efficient membrane solutions.

Learn more on CR6 composite membrane application in the following study : A Combined Gas and Water Permeances Method for Revealing the Deposition Morphology of GO Grafting on Ceramic Membranes

Adaptive Driving Beam (ADB) is a smart system that can automatically adjust the light distribution of the headlights according to the traffic conditions, such as the presence of oncoming vehicles or pedestrians. By creating a glare-free area around vehicles, ADB can provide optimal illumination at long distances for the driver without dazzling other road users, enhancing both safety and comfort at night. ADB technology rely on perception systems that gather data, software controls that trigger an appropriate response, and advanced headlamp optics incorporating YAG converters to carry out the command.

Light conversion phosphors role in the solid-state lighting and ADB technology?

The light source is a key component for ABD, which is usually based on LED (light-emitting diode) technology and light changes are mainly controlled with a LED matrix design.

If LED have efficiency, long lifetime, low power consumption and fast response advantages over conventional halogen or xenon lamps, they also have color light rendering and thermal stability challenges. For high-power applications such as ADB, thermal stability and luminescent efficiency of phosphors can overcome these drawbacks.

Indeed, light conversion phosphors are materials that can absorb light of a certain wavelength (usually blue or near-ultraviolet) and re-emit light of a different wavelength (usually yellow or red). By combining the original and the converted light, white light with a desired color temperature and color rendering index can be obtained. The ideal color temperature for headlight should be close to the sunlight (around 5000K-6000K) in order to provide optimal visibility for human eyes.

One of the most widely used light conversion phosphors for white LEDs is YAG:Ce3+ (yttrium aluminum garnet doped with cerium ions) that efficiently convert blue into yellow light, resulting in a warm white light with a high luminous efficacy. By producing a high brightness and contrast ratio, it helps to create a clear and sharp image on the road.

Baikowski® high crystallinity, phasic and chemical purity submicronic YAG:Ce powder offers optimized particle size and distribution that allows the production of YAG-based converters with outstanding performances such as:

• 🌟 High efficiency with minimal energy wasted as heat and high light-performance from the input source
• 🌟 A quick and accurate response to the input signal for precise adjustments.
• 🌟 Exceptional stability in both light color and brightness

Fully compatible with nanostructured blue diodes and various LED chip designs, our YAG nanophosphors enable device miniaturization>

Learn more about Baikowski® unique submicronic YAG powders

Custom YAG-based converters for high-performance ADB lighting

By doping, enhanced performance of YAG:Ce3+ can be achieved. Here are some examples that could comply with your ADB lighting specification needs:

• 🌟 Color rendering: Doping YAG:Ce3+ with Tb3+ (terbium ions) allows a broader emission spectrum that improves the color rendering index of the white light.
• 🌟 Emissive properties and stability: the addition of gadolinium (Gd3+) ions as a codopant ensures consistent color and brightness
• 🌟 Quantum efficiency: Europium codoping can boost the quantum efficiency of the YAG:Ce phosphor, resulting in enhanced light output

Do not hesitate to contact our commercial and R&D teams for tailored YAG design.

LED technology: a sustainable lighting & display solution

Light Emitting Diodes (LEDs) have revolutionized various industries, by providing energy-efficient solutions with less environmental impact than traditional lighting for a wide range of applications, including display screens, car displays and lightings, electronics and smart devices.

Thanks to to the direct conversion of electrical current into light (optical radiation) within the semiconductor material, LEDs exhibit this remarkable level of efficiency. However, a significant portion of the electrical power is also transformed into heat during the process.

High Purity Alumina, YAG & nanomaterials role in advanced LED technology

High Purity Alumina (HPA) plays an essential role in producing the substrate, which serves as a foundation for the LED chip, affecting its overall performance, thermal management, and efficiency. Thanks to its exceptional ability to resist high temperatures, conduct heat efficiently, and insulate against electrical conductivity, LED lights can operate at their maximum potential.

As a highly efficient heat-dissipating component, High Purity Alumina (HPA) has contributed to the LED technology sustainability. Indeed, by maintaining LEDs at optimal temperatures, they maximize their performance and extends their operational lifespan, about 30,000 hours, equivalent to 6 hours of daily illumination for 12 years.

HPA has also influences the optical performance of LED lights, particularly in applications demanding color purity and accuracy. Its uniform crystal structure enhance light diffraction and color consistency in applications like display screens and specialized lighting.

Beyond HPA, Baikowski® also manufactures phosphors, used among other things for generating a broader spectrum of colors, such as its submicronic YAG product that offers a natural-looking white light. For instance, it is used in white LEDs and plasma display panels, as well as adaptive headlights to create different colors and intensities of light depending on the driving situation and the environment.

💡 As technology continues to evolve, Baikowski® finely-tuned oxides solutions and Mathym® advanced nanomaterials, that offer high crystallinity and controlled specific surface area, will have a role to play in the progress of emerging optics applications like mini-LED and micro-LED displays.💡

Integrating the superior performances of Mathym® nanoparticles, such as zilight®  into nanoscale structures or coatings, not only enables the miniaturization of optical devices, but also facilitates integration with other technologies, paving the way for the development of compact and multifunctional  LED lighting solutions. Learn more about optical coating with zilight®, including case studies, in our dedicated white paper.

🌟 Whether it’s LED lighting or cutting-edge displays, Baikowski® group is here to cater to your specific needs.🌟

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