In the field of high-temperature metallurgy and induction melting, the purity and stability of the crucible directly influence the cleanliness and performance of the end material. For companies producing nickel-based superalloys, precious metals, and advanced ceramics, a High-Purity Magnesium Oxide (MgO) Crucible is increasingly becoming the core refractory container.
High resistance to metal oxides and alkaline slags;
Superior chemical stability compared to Al₂O₃;
Good electrical insulation and relatively low thermal expansion. These characteristics make MgO the preferred crucible material for induction furnaces , induction melting furnaces, and electron-beam melting equipment.
WEIERT Ceramics’ Manufacturing Approach
Based on studies of high-purity MgO ceramics (e.g., industry data showing >99 % MgO content and high bulk density), Weiert Ceramics applies advanced forming and refining techniques to ensure excellent structural stability and consistency.
Our process combines Cold Isostatic Pressing (CIP) for uniform particle distribution and high densification, together with electrofused re-crystallisation to achieve oriented grains and ultra-low impurities.
Sintering parameters are precisely controlled, and with ultra-pure MgO feedstock the resulting crucibles reach purity levels above 99.5 % and bulk density around 3.4 g/cm³, providing outstanding thermal and chemical stability.
Anti-hydration and long-term stability
Because MgO is prone to hydration, we adopt the following improvements:
Micro-additions of Al₂O₃, CaO and Ga₂O₃ to improve densification and reduce residual porosity;
Surface sol–gel pore-sealing coatings;
Vacuum-sealed, moisture-controlled packaging during storage and transport.
Performance & applications
High-purity MgO crucibles are used in:
Induction melting of nickel-based superalloys;
Refining of platinum, iridium, palladium and other precious metals;
Melting of lithium-ion cathode precursor materials, rare-earth oxides, and high-purity metal melts. Independent factory data show that in a 1,700 °C vacuum environment, Weiert Ceramics’ crucibles achieve continuous operation of over 20 hours without structural failure.
Summary
High-purity MgO crucibles represent the high-end direction of refractory ceramic materials. Weiert Ceramics, leveraging ultra-pure raw materials and custom sintering processes, offers customers crucible solutions with higher purity and longer service life.
References:
Jin Yan, Development of Magnesia Crucible Products, Ceramics, 2006.
Chen Guangyao et al., Interface Reaction Mechanism between MgO Crucible and Ni-Based Superalloy, Journal of the Chinese Ceramic Society, 2024.
Wu Chaowan, Studies on MgO Crucible in Vacuum Induction Furnace for Pure Iron Melting, Acta Metallurgica Sinica, 1964.
