Flexural Strength of Advanced Ceramics

Flexural strength, also known as bending strength or modulus of rupture, is a critical mechanical property that defines how much stress a material can withstand before it breaks under a bending load. In advanced ceramics, flexural strength plays a vital role in determining performance in structural, wear, and thermal shock applications.

Unlike metals that yield before breaking, ceramics are brittle and fail without plastic deformation. This makes their flexural strength especially important in design and engineering calculations.

Skip to

Data | Comparison | Applicatons | FAQs | Related

Hardness of Ceramics: Properties, Comparison & Applications

Why Choose Ceramics for High Flexural Strength Applications?

Advanced ceramics are preferred in high-performance components for several reasons:

  • High Strength-to-Weight Ratio: Ceramics like silicon nitride and zirconia provide exceptional mechanical strength while being lightweight.
  • Superior Thermal Stability: Ceramics retain flexural strength even at temperatures >1000°C, outperforming most metals and plastics.
  • Wear and Corrosion Resistance: Ideal for environments involving chemicals, abrasives, or moisture.
  • Dimensional Stability: No plastic deformation under load, ensuring consistent tolerances.
  • Extended Lifetime: Long-lasting even in cyclic loading and fatigue scenarios.

Flexural Strength Data of Key Advanced Ceramics

Ceramic Material Flexural Strength (MPa)
Zirconia (ZrO₂) 800–1200
Silicon Nitride (Si₃N₄) 700–1200
ZTA (Zirconia Toughened Alumina) 600–800
Silicon Carbide (SiC) 400–600
Alumina (Al₂O₃, 99.7%) 300–500
Aluminum Nitride (AlN) 300–400
Boron Carbide (B₄C) 200–400
Beryllium Oxide (BeO) 150–250
Machinable Glass Ceramic 100–150

*Data is for reference only.

Comparison Chart: Ceramics, Metals, and Plastics

The bar chart below shows the flexural strength (MPa) of various engineering materials, ranging from super-hard ceramics to common industrial plastics, in descending order.

Ceramic
Metal
Plastic

*Data is for reference only.

*Conclusion: While many metals are tough and ductile, only a few (like titanium alloys) approach the flexural strength of top ceramics. Plastics generally lag far behind.

Need Help Choosing the Right Ceramic?

Choosing the right ceramic material for high flexural strength is critical to ensuring long-term reliability and peak performance. Whether you require Zirconia, Silicon Nitride, or Alumina-based ceramics, our materials offer industry-leading strength, durability, and precision.

Our technical team is here to help — contact us today for expert, customized recommendations based on your specific requirements.

Applications based on ceramic Flexural strength

  • Application: Wafer support plates in deposition or etching chambers.
  • Why: These plates are subjected to repeated thermal cycles and mechanical loads.
  • Advantages: Ceramics have high flexural strength (~900–1000 MPa), excellent thermal shock resistance, and dimensional stability.
  • Benefits: Prevents warping or cracking during high-temperature processing, improves device yield and process reliability, extends service life in harsh environments, etc.

  • Application: Plunger components in abrasive or corrosive fluid pumps
  • Why: Plunger withstands cyclic bending and compression forces under high pressure.
  • Advantages: SSiC combines flexural strength of ~800–1000 MPa with excellent corrosion resistance.
  • Benefits: No deformation or fracture under mechanical loads, Excellent performance in corrosive chemical environments, Low maintenance, Long service life

  • Application: Hybrid ceramic ball bearings
  • Why: Balls are subject to radial loads, centrifugal forces, and micro-vibrations during operation.
  • Material Advantages: Silicon nitride is lightweight and has excellent strength and fatigue resistance.
  • Advantages: Higher RPM without thermal deformation, Longer service life compared to steel bearings, Operates without lubrication in vacuum or high temperature conditions.

  • Application: High-power LED submounts and chip carriers
  • Why: Thin ceramic substrates must resist mechanical bending and thermal stress.
  • Advantages: AlN offers flexural strength of ~300–400 MPa and thermal conductivity >170 W/m·K.
  • Advantages: Maintains structural integrity under thermal cycling, supports miniaturization of power devices, enables efficient heat dissipation, and long-term reliability.

  • Application: Insulation rods and structural brackets in substations
  • Why: Mechanical loads from wind, cables and environmental stresses require high rigidity.
  • Advantages: Alumina ceramics have reliable strength (300–450 MPa) and long-term outdoor durability.
  • Benefits: Reliable support structure for electrical components, minimized aging in outdoor conditions, excellent mechanical and dielectric properties.

  • Application: Ceramic friction elements in brake systems
  • Why: Brake pads must resist shear and bending forces during repeated thermal cycles.
  • Advantages: ZTA (zirconia toughened alumina) provides enhanced toughness and bending strength (~600–800 MPa).
  • Benefits: Improved wear resistance, longer service life compared to metal systems, enhanced safety under extreme braking conditions.

  • Applications: Structural support arms in CT, X-ray and robotic devices
  • Why: Support arms require precise dimensions and stiffness under static or dynamic loads.
  • Advantages: MGC offers a bending strength of approximately 150 MPa and can be machined to tight tolerances.
  • Benefits: High dimensional accuracy, easy to machine, electrically insulating and thermally stable, ideal for custom small batch production.

Frequently Asked Questions (FAQ)

Flexural strength is the maximum stress a material can withstand in bending before it fails. It’s critical for brittle materials like ceramics.

Because ceramics cannot plastically deform, their ability to withstand bending loads before breaking is key to reliability in structural applications.

Silicon nitride and zirconia are among the strongest, with values often exceeding 1000 MPa.

Some ceramics outperform metals in flexural strength, especially when considering weight-to-strength ratio, but they are more brittle and require careful design to prevent fracture.

Flexural strength is commonly tested using three-point or four-point bending techniques (ASTM C1161).

High purity, grain structure, and strong ionic/covalent bonding give ceramics superior strength with low creep and wear.

No. Zirconia and silicon nitride are among the strongest. Machinable ceramics have lower strength but easier processability.

Thermal conductivity of silicon carbide ceramics