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GA Magnesia Ceramic（MgO）
What is Magnesia (MgO) Ceramic?Magnesia (MgO) ceramic is a type of advanced ceramic that also falls under the category of traditional refractory materials. MgO has excellent resistance to corrosion by alkaline metal solutions. Its chemical and radiation stability make it an important material for nuclear power applications.
The theoretical maximum operating temperature of MgO ceramics is 2200°C, and they can be used continuously at 1600–1800°C. This makes MgO ceramics a key material for advanced processes in modern metallurgical industries.
The disadvantages of magnesia ceramics include slightly inferior thermal shock resistance and the highly reactive nature of magnesium, which readily reacts with oxygen, nitrogen, and water vapor. When used in a vacuum environment, its application is subject to strict limitations regarding vacuum pressure and the choice of certain inert gases under vacuum conditions.
Preparation of Magnesia (MgO) Materials:
Raw Material Extraction:
Magnesia (MgO) is mainly extracted from minerals or seawater. Typically, it is first converted into magnesium hydroxide (Mg(OH)₂) or magnesium carbonate (MgCO₃). These compounds are then calcined (heated) to produce MgO. To obtain high-purity MgO, additional chemical or thermal treatments are applied.
Ingredient Mixing and Modifications:
During preparation, the composition of MgO is carefully adjusted. To improve sintering, slightly increase grain size, and reduce the tendency of hydration, small amounts of additives such as TiO₂, Al₂O₃, or V₂O₃ can be added.
High-Purity MgO Processing:
For applications requiring high-purity MgO ceramics, additives cannot be used. Instead, an activated sintering method is applied:
- Magnesium hydroxide (Mg(OH)₂) is calcined at a suitable temperature to create active MgO with many lattice defects.
- This active MgO is then sintered to produce high-performance magnesium oxide ceramics.
This method ensures excellent purity and performance, meeting the needs of demanding applications.
Magnesia(MgO)Ceramic Properties Table
| Property | Unit | Value |
| Purity | % | MgO ：99.7% |
| Colour | white | |
| Water absorption | % | 5.5 |
| Density | cm³ | 3.4 |
| Water Absorption | g/% | 6.5 |
| Flexural Strength (MOR) (3 point) @ RT |
Mpa | 215 |
| Therm. Conductivity (400°C) | W/m-K | 44 |
| CTE (20-1000°C) | 10-6/K-1 | 13 |
| Max.Oper. Temp. Air | °C | 2200 |
| Cont.Oper. Temp. Air | °C | 1800 |
| Specific Heat Capacity | J/g-°C | 0.900 |
*The values represent typical material properties and may vary depending on product configuration and the manufacturing process,
For further information, do not hesitate to contact us.
Common Types of Magnesium Oxide Ceramic Materials:
Magnesia MgO Ceramic
Magnesium Aluminate Spinel
Porous Magnesia Ceramics
Magnesium aluminate spinel ceramic, with the chemical formula MgAl₂O₄, is an advanced ceramic material widely used for crucibles. Compared to magnesia (MgO) ceramics, it is co-sintered with 50%-70% Al₂O₃ and magnesium oxide, resulting in a dense and vitrified structure. This composition provides higher thermal shock resistance, making it particularly suitable for melting magnesium alloys and other highly reactive alloys.
In the past, iron-based crucibles, such as those made from carbon steel or stainless steel, were commonly used for casting magnesium alloys. However, these materials are highly susceptible to corrosion by molten metals and fluxes, leading to short service life. Furthermore, the iron content in the crucibles can leach into the molten alloy, causing contamination.Graphite crucibles, although offering high thermal conductivity, have low mechanical strength and are prone to cracking under uneven heating conditions.
Magnesium alloys pose unique challenges due to their high vapor pressure (e.g., 1037 Pa at 727°C). Molten magnesium and its vapors easily penetrate porous ceramic materials, reacting with them and generating stresses that cause material degradation. This results in structural damage, material peeling, and contamination of the molten alloy.
Superior Properties of Magnesium Aluminate Spinel CeramicsMagnesium alloys exhibit high chemical reactivity and can react with traditional ceramic materials such as Al₂O₃, ZrO₂, SiC, and SiO₂. Additionally, during melting and refining, magnesium easily reacts with oxygen, nitrogen, and water vapor, leading to oxidation losses and residual by-products. These impurities can affect the quality and performance of magnesium alloy products. Magnesium aluminate spinel ceramic (MgAl₂O₄) addresses these problems effectively. Its dense microstructure and superior oxidation resistance prevent the infiltration of molten magnesium and vapors. The addition of Al₂O₃ enhances densification during sintering, further improving its structural integrity. As a result, this material is the preferred choice for processing high-purity iron and its alloys, as well as nickel, uranium, thorium, zinc, tin, aluminum, and their alloys.
WEIERT Ceramics Technology is the best manufacturer of magnesium aluminate spinel ceramics in China. We are not only a producer of magnesium aluminate spinel crucibles but also offer custom services for magnesium aluminate spinel ceramic products. Feel free to contact us for any inquiries or requirements!
Porous ceramics are materials formed by sintering magnesium oxide at high temperatures, resulting in a structure with numerous internal pores. Porous magnesia ceramics are produced using high-purity magnesium oxide with a magnesium content exceeding 95%. In contrast, non-porous or dense magnesium oxide ceramics (porosity < 0.1%) typically require the addition of other components, and their magnesia content usually ranges between 60–80%.
Based on pore size, porous magnesia ceramics can be classified into micropores and macropores. Micropores are essential for adsorption and purification processes involving gases or liquids, including catalytic purification. Macropores, on the other hand, play a critical role in filter cleaning systems, thermal insulation, and biomedical applications.
The Applications of Magnesia Ceramic :
Magnesia ceramics outperform alumina ceramics in both high-temperature stability and corrosion resistance. it has a wide range of applications, including:
- Crucibles and Refractories: Used in steel and glass smelting industries, especially under corrosive conditions.
- Metal Processing: Suitable for melting metals and alloys, such as nickel alloys, radioactive uranium and thorium alloys, and iron and its alloys.
- Nuclear Industry: Ideal for melting high-purity uranium and thorium in atomic energy applications.
- Thermocouple Protection Tubes: Provides thermal and chemical protection for sensors.
- Electromagnetic and Optical Components: Utilized in radar domes and infrared radiation projection windows due to its ability to transmit electromagnetic waves.
- Sintering Supports: Serves as sintering carriers for ceramics, especially for processing corrosive and volatile substances like β-Al₂O₃ at high temperatures.
- Piezoelectric and Superconducting Materials: Acts as raw material for specialized applications, offering properties such as lead corrosion resistance and non-contamination.
MgO ceramics’ combination of high-temperature performance, chemical stability, and corrosion resistance makes them indispensable for demanding industrial and scientific applications.
WEIERT Ceramics Technology is the best MgO Ceramic company in China.
We provide customized magnesia ceramic tubes, magnesia ceramic rings, magnesia blocks, and various complex magnesia ceramic components.
