Custom Silicon Nitride Ceramic Crucible Si3N4 ceramic pot for Melting Precious Metal

Brief

Silicon nitride crucible is a crucible made mainly from silicon nitride, which has the advantages of high temperature resistance, corrosion resistance, wear resistance, etc. It is commonly used for melting metals, ceramics and other materials.

Details

Silicon nitride high hardness crucible provides the best balance of hardness, toughness, thermal stability, and chemical inertness in harsh melting scenarios that require resistance to severe wear, metal melt erosion, high temperature deformation, and frequent thermal cycles, making it particularly suitable for precision melting of high-value metals.

Application of the Si3N4 ceramic crucible：

• High purity/active metals: Melting high-purity silicon (photovoltaic, semiconductor grade), germanium, gallium, indium, etc. to avoid carbon and oxygen pollution, ensuring hardness and resistance to silicon melt erosion.
• Precious metals: Melting gold, silver, platinum group metals and their alloys, high hardness to resist melt flow erosion, chemical inertness to ensure melt purity.
• High temperature alloys/refractory metals: Melting titanium alloys, nickel based high-temperature alloys, molybdenum alloys, etc., with high temperature strength and thermal shock resistance meeting requirements.

Features

• Ultra high hardness and wear resistance: The Vickers hardness of 15-18 GPa makes it one of the hardest engineering ceramics, second only to diamond, cubic boron nitride, and some silicon carbide ceramics. This endows the crucible with excellent resistance to metal melt erosion, slag erosion, and particle wear, significantly extending its service life.
• Excellent high-temperature strength and creep resistance: It can maintain high strength even at high temperatures (up to 1400 ° C), with outstanding resistance to high-temperature deformation (creep), ensuring the structural integrity and dimensional stability of the crucible during long-term high-temperature melting.

Excellent thermal shock resistance: The combination of low thermal expansion coefficient (~3.2 × 10 ⁻⁶/K) and moderate thermal conductivity (~20-30 W/mK) enables it to withstand severe temperature fluctuations during the melting process (such as feeding and discharging) without cracking.

• Good chemical stability: It is inert to most metal melts (especially non-ferrous metals) and molten salts, and is not prone to chemical reactions or contamination of the melt. Form a protective SiO ₂ layer on the surface in an oxidizing atmosphere to enhance corrosion resistance.
• Low wettability: It has a large contact angle with many molten metals such as aluminum, copper, and their alloys, making it difficult to adhere to the metal and facilitating the pouring of the melt and cleaning of the crucible.

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