High-Strength Silicon Nitride Ceramic Stepped Bolt - Reliable Connection

Product Specification

High-Strength Silicon Nitride Ceramic Stepped Bolt - Reliable Connection Solution for Extreme Environments

Product Overview

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.

Core Advantages

1. 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.

2. 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.

3. 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.

Typical Applications

• 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.

Specification Table

Manufacturing Process

1. Powder Processing: High-purity α-Si₃N₄ powder (particle size ≤1μm) mixed with sintering additives.

2. Forming Process: Cold isostatic pressing (CIP) for preliminary shaping, CNC engraving for threads and slots.

3. Sintering Technology: Gas pressure sintering (1700-1900℃, nitrogen atmosphere), density >99%.

4. Precision Machining: Diamond grinding and polishing, surface roughness Ra≤0.2 μm.

5. Quality Inspection: Ultrasonic flaw detection, dimensional inspection with CMM, Weibull modulus ≥12.

Usage Instructions

1. 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.

2. Environmental Limitations

   • Avoid contact with hydrofluoric acid or hot concentrated alkali solutions (pH＞12).

   • Control temperature change rate to ≤200℃/minute.

3. Maintenance Recommendations

   • Inspect thread wear every 1000 hours of operation, clean with anhydrous ethanol.

After-Sales Service

• 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.

FAQ

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.