Machinery and Industrial Manufacturing

Alumina (Al₂O₃), zirconia (ZrO₂), silicon carbide (SiC), and silicon nitride (Si₃N₄) are all high-performance advanced ceramics. Their exceptional physical and chemical properties make them indispensable key materials in modern manufacturing.

Alumina is the most widely used, technologically mature, and lowest-cost engineering ceramic. It balances performance and price by controlling purity (95%, 99%, etc.).

Core Advantages: High hardness, excellent wear resistance, outstanding electrical insulation, excellent corrosion resistance, and low cost.

Specific Applications:

• Wear-resistant components: Seals, valve bushings, nozzles, textile ceramics, and grinding media (ceramic balls).
• Electrical insulators: Circuit boards, spark plugs, and high-voltage insulating sleeves.
• Corrosion-resistant components: Linings and components for chemical pumps and valves.
• High-temperature components: Furnace tubes, thermocouple protection tubes, and refractory materials.

Zirconia is the most representative toughened ceramic. Through phase transformation toughening technology, its fracture toughness is far superior to other ceramics, overturning the traditional impression of ceramics as "brittle."
It features extremely high fracture toughness and flexural strength, high wear resistance, low coefficient of friction, and excellent biocompatibility. Its toughness is closest to that of metal.

Specific Applications:

• Structural and Wear-Resistant Parts: Ceramic bearings, hammer blocks, scissors, knives, optical fiber sleeves, and wear parts.
• Medical: Hip joint balls, dental implants, and crowns and bridges (due to their high toughness, low wear, and biocompatibility).
• Daily Use and Precision: Ceramic knives, watch cases, and smartphone back panels (after toughening, they are aesthetically pleasing and scratch-resistant).
• Sensors: Oxygen sensors (utilizing their ionic conductivity).

Silicon carbide is a covalently bonded super ceramic, available in both reaction-sintered and pressureless sintered forms, offering exceptional performance. 

Core Advantages: Extremely high hardness and wear resistance, excellent high-temperature strength (no softening at 1600°C), extremely high thermal conductivity (excellent heat dissipation), low thermal expansion coefficient (excellent thermal shock resistance), and chemical corrosion resistance.

Specific Applications:

• High-Temperature Kiln Furniture: Kiln rollers, setters (lightweight, long life, energy-saving), heat exchangers.
• Wear Resistance and Sealing: Mechanical seals, slurry pump components, sandblasting nozzles, used in extremely harsh operating conditions.
• Lightweighting and Armoring: Lightweight, high-performance ceramic armor plates for aerospace and armored vehicles.
• Semiconductors and Electronics: Wafer grinding discs, epitaxial wafer susceptors, and heat sink substrates for high-power electronic devices (leveraging its high thermal conductivity and insulation).

Silicon nitride is one of the ceramic materials with the best overall performance, combining high strength, high toughness, low density, excellent thermal shock resistance, and wear resistance. 

Core Advantages: Optimal strength-to-weight ratio, outstanding thermal shock resistance (resistance to rapid cooling and heating), high fracture toughness, self-lubricating properties, low density, and high hardness.

Specific Applications:

• Bearings: Full ceramic bearings or hybrid ceramic bearings (Si₃N₄ balls) are used in high-speed, high-precision, corrosive, and non-lubricated environments (such as machine tool spindles and aerospace applications).
• Metal Processing: Rolling mill rolls, horizontal continuous casting molds, and thermocouple protection tubes, as they do not wet most molten metals (such as aluminum and zinc).
• High-temperature structural parts: Gas turbine blades, turbine rotors, and engine components. They are key materials for improving thermal efficiency in the future.
• Cutting Tools: Used for high-speed cutting of difficult-to-machine materials such as cast iron and high-temperature alloys.

When choosing between these four ceramics, consider the key requirements of the specific application scenario:

• For cost-effectiveness and electrical insulation: Alumina is the preferred choice.
• For high toughness and impact resistance, as a metal replacement: Zirconia is the preferred choice.
• For extreme high temperatures requiring excellent thermal conductivity and heat dissipation: Silicon carbide is the preferred choice. The pursuit of pinnacle comprehensive performance requires exceptional thermal shock resistance, high strength, and low weight: regardless of cost, choose silicon nitride.

These four materials collectively drive the mechanical and industrial manufacturing industries toward high-temperature, high-efficiency, high-reliability, and lightweight development, offering the ultimate solution to material bottlenecks in many extreme operating conditions.