Dayoo Advanced Ceramic Co.,Ltd
Dayoo Advanced Ceramic Co.,Ltd
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This product is a precision-machined stepped bolt made of high-performance silicon nitride ceramic, specifically designed for high-temperature, highly corrosive, and precision mechanical environments. The bolt features an overall gray-black matte texture, with a structure comprising an external threaded cylinder, a smooth transition section, and a hexagonal nut with a slotted design, combining installation convenience with structural stability. Silicon nitride ceramic, with its high hardness, low density (3.2-3.3 g/cm³), and high-temperature resistance (up to 1200℃), significantly outperforms metal materials, making it suitable for high-end applications such as semiconductors and aerospace.
Exceptional Mechanical Performance
Flexural strength ≥800 MPa, fracture toughness 6-8 MPa·m¹/², hardness ≥1500 Hv, capable of withstanding high loads and impact.
Low friction coefficient (0.1-0.3) and self-lubricating properties, reducing wear and extending service life 5-10 times longer than metal bolts.
Adaptability to Extreme Environments
High-temperature resistance: Stable operation in oxidizing atmospheres up to 1200℃, withstanding thermal shock temperature differences exceeding 800℃.
Corrosion resistance: Resists strong acids, alkalis, and organic solvents (except hydrofluoric acid), suitable for chemical and semiconductor cleanrooms.
Electrical insulation: Room temperature resistivity ≥10¹⁵ Ω·cm, avoiding electromagnetic interference.
Precision Structure and Lightweight Design
Thread tolerance ±0.005 mm, hexagonal nut compatible with standard tools, density only 3.2 g/cm³, 60% lighter than steel components.
Semiconductor Manufacturing: Fasteners for wafer handling arms, sealing connections for vacuum chambers, resistant to organic solvent erosion.
Aerospace: High-temperature zone components for engines, sealing bolts for liquid hydrogen pumps, stable from ultra-low to high temperatures.
Energy and Chemical Industries: Valves for liquefied natural gas (LNG), sealing systems for nuclear reactors, resistant to high pressure and corrosive media.
Precision Machinery: Preload bolts for high-speed spindle bearings, replacing metal to reduce inertia and thermal deformation.
| Parameter | Technical Index |
|---|---|
| Material Composition | Si₃N₄ ≥93%, Y₂O₃-MgO additives |
| Density | 3.20-3.28 g/cm³ |
| Flexural Strength | 750-850 MPa |
| Fracture Toughness | 6.5-7.5 MPa·m¹/² |
| Vickers Hardness | HV0.5 1500-1700 |
| Maximum Service Temperature | 1200℃ (in air) |
| Thermal Expansion Coefficient | 3.2×10⁻⁶/℃ |
| Thread Precision | ±0.005 mm |
Powder Processing: High-purity α-Si₃N₄ powder (particle size ≤1μm) mixed with sintering additives.
Forming Process: Cold isostatic pressing (CIP) for preliminary shaping, CNC engraving for threads and slots.
Sintering Technology: Gas pressure sintering (1700-1900℃, nitrogen atmosphere), density >99%.
Precision Machining: Diamond grinding and polishing, surface roughness Ra≤0.2 μm.
Quality Inspection: Ultrasonic flaw detection, dimensional inspection with CMM, Weibull modulus ≥12.
Installation Specifications
Use a torque wrench with recommended preload force ≤30 N·m to avoid brittle fracture from overloading.
When mating with metal components, adding a BN coating is recommended to reduce thermal mismatch stress.
Environmental Limitations
Avoid contact with hydrofluoric acid or hot concentrated alkali solutions (pH＞12).
Control temperature change rate to ≤200℃/minute.
Maintenance Recommendations
Inspect thread wear every 1000 hours of operation, clean with anhydrous ethanol.
Quality Assurance: 18-month product warranty, lifetime technical support.
Customization Services: Support for non-standard thread sizes and head structure customization, delivery period 15-30 days.
Emergency Response: Fault analysis within 24 hours, replacement parts shipped within 48 hours.
Q1: Is performance stable in liquid hydrogen environments (-253℃)?
A1: Yes, silicon nitride does not undergo brittle transition at ultra-low temperatures, with strength and toughness even exceeding room temperature performance. It has passed 10⁷ cycle tests for liquid hydrogen pump seals.
Q2: Can it be directly mated with aluminum alloy components?
A2: It is recommended to add a flexible gasket, as the thermal expansion coefficient of aluminum (23×10⁻⁶/℃) is much higher than that of silicon nitride (3.2×10⁻⁶/℃), requiring compensation for thermal displacement.
Q3: What is the maximum tensile load?
A3: The ultimate tensile load for an M6 specification bolt is ≥35 kN, with a recommended safety factor of 3.
