Lightweight: With a density of only 3.2 g/cm³, it is approximately 40% the density of bearing steel, significantly reducing centrifugal force during high-speed rotation and lessening the burden on equipment.
Hard: Vickers hardness reaches 1400-1800 HV, more than twice that of ordinary bearing steel, making it wear-resistant and durable, extending its lifespan by 5-8 times.
Stable: The thermal expansion coefficient is only 1/4 that of steel, maintaining dimensional stability from -100℃ to 1200℃, preventing "jamming" due to sudden temperature changes.
Insulating: At room temperature, the volume resistivity is as high as 10¹⁴-10¹⁶ Ω·cm, effectively blocking current erosion, which is a crucial "life-saving feature" in new energy equipment.
Silicon nitride bearing balls (Si₃N₄) are high-performance structural ceramic rolling elements widely used in bearing systems requiring high speed, high temperature, high corrosion resistance, and high reliability. They are considered an important upgrade and alternative material to metal bearing balls (such as bearing steel). Silicon nitride bearing balls are primarily made of sintered Si₃N₄ (silicon nitride) and belong to the category of non-oxide structural ceramics. Their microstructure is dense with fine grains, possessing both high strength and high toughness, resulting in outstanding overall performance among engineering ceramics.
Use Cases
1. Applications in New Energy Vehicles: The drive motor of a new energy vehicle is its "heart," and the bearing balls are the "heart valves"—if they malfunction, the motor will directly "stop working." However, the environment inside the motor is a "hellish" one: rotational speeds reach up to 27,000 revolutions per minute, and it's filled with alternating electromagnetic fields that easily generate shaft currents. Silicon nitride bearing balls have the characteristics of resistance to electrical corrosion, reduced energy consumption, and high-temperature resistance.
2. Applications in Dental Drills: The "whirring" sound you hear when getting your teeth checked comes from ultra-high-speed rotation of 450,000 revolutions per minute—this places "extreme" demands on the bearing balls: they must be miniature (diameter only 1-2.381mm) and able to withstand extreme rotational speeds. Silicon nitride bearing balls play a role in providing stable, quiet operation, long lifespan, and safety and reliability.
3. Applications in Roller Skates: Roller skating enthusiasts understand that the jerky feeling and bearing noise during skating are mostly caused by wear or rust of the steel balls. Silicon nitride ceramic balls perfectly solve these problems: ultra-smooth, waterproof, and impact-resistant.
4. Applications in High-End Bicycles: For cycling enthusiasts, especially mountain bike and road bike riders, bearing performance directly affects the riding experience. Silicon nitride ceramic balls in the hubs and bottom bracket bearings of bicycles offer three major advantages: effort-saving and energy-efficient, durable and robust, and stable and precise.
Performance parameters
performance | unit | ZrO₂ | Si₃N4 | SiC | Ai₂O3 |
density | g/cm³ | 6-6.05 | 3.22-3.25 | 3.15-3.2 | 3.85-3.92 |
hardness | kg/mm | 1250 | 1600 | 2450 | 1800 |
toughness | MN/m | 7.0 | 6.0 | 2.5 | 3.0 |
Bending strength | kgf/cm³ | 100-120 | 80-100 | 40-50 | 30-40 |
Thermal shock resistance | △T，℃ | 280 | 900 | 400 | 200 |
Coefficient of thermal expansion | x10-6/℃ | 9.0 | 3.5 | 4.2 | 7.0 |
Operating temperature | ℃ | 400 | 1200 | 1500 | 1600 |
Corrosion resistance (acids and bases) | / | Good | Good | Excellent | Excellent |
Thermal conductivity | w/mk | 3.0 | 29 | 120 | 23 |
Fatigue life | / | 80x | 100x | 50x | 40x |
magnetic | / | Non | Non | Non | Non |
Insulation | // | Insulation | Insulation | Insulation | Insulation |
Compressive strength | Mpa | 2000 | 3500 | 2250-300 | 2800-3500 |
fracture toughness | Mpa:m-3/2 | 11 | 7 | 4-5 | 2-4 |
Weber modulus | GPa | >15 | >15 | >6 | >6 |
Elastic modulus | GPa | 210 | 320 | 410 | 420 |
Poisson's ratio | / | 0.3 | 0.26 | 0.26 | 0.2 |
resistance | mm2/m | >10 | >10 | 100-2 | >10 ->10 |
resistivity | mm2/m | 1015 | 1018 | / | / |
Specific heat | J/KgK | 400 | 800 | / | / |
Number of stress cycles (50% probability of failure) | / | 50*106 | 50*106 | / | / |
Failure modes due to rolling contact fatigue | / | Peeling/Cracking | peeling off | / | / |
Dimensional stability | / | good | good | good | good |
Supports custom specifications.
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