Flexural strength of advanced ceramics

Flexural strength, also known as bending strength or modulus of rupture, is a key mechanical property that determines the amount of stress a material can withstand before it breaks under bending loads. In advanced ceramics, flexural strength plays a critical role in determining their performance in structural, wear and thermal shock applications.

Unlike metals, which yield and then break, ceramics are fragile and do not deform plastically. Therefore, the flexural strength of ceramics is particularly important in design and engineering calculations.

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Why choose ceramics for high flexural strength applications?

Advanced ceramics are the first choice for high performance components for the following reasons:

High strength-to-weight ratio: Ceramics such as silicon nitride and zirconium oxide are lightweight and at the same time have excellent mechanical strength.
Excellent thermal stability: ceramics maintain flexural strength even at temperatures >1000°C, outperforming most metals and plastics.
Abrasion and corrosion resistance: suitable for environments containing chemicals, abrasives or moisture.
Dimensional stability: no plastic deformation under load, ensuring consistent tolerances.
Extended service life: long-lasting durability even under cyclic loads and fatigue.

Flexural strength data for key advanced ceramics

Ceramic materials	Flexural strength (MPa)
Zirconium oxide (ZrO₂)	800-1200
Silicon Nitride (Si₃N₄)	700-1200
ZTA (Zirconia Toughened Alumina)	600-800
Silicon Carbide (SiC)	400-600
Aluminum oxide (Al₂O₃, 99.7%)	300-500
Aluminum Nitride (AlN)	300-400
Boron carbide (B₄C)	200-400
Beryllium oxide (BeO)	150-250
Glass ceramics can be processed	100-150

*Data is for reference only.

Comparison table: ceramics, metals and plastics

The bar charts below show, in descending order, the flexural strength (MPa) of a variety of engineering materials, ranging from super-hard ceramics to common industrial plastics.

Ceramic

Metal

Plastic

*Data is for reference only.

*Conclusion: While many metals are tough and ductile, only a few (e.g., titanium alloys) approach the flexural strength of top-quality ceramics. Plastics are usually far behind.

Need help choosing the right ceramic?

Choosing the right high flexural strength ceramic material is critical to ensuring long-term reliability and optimal performance. Whether you need zirconia, silicon nitride, or alumina-based ceramics, our materials provide industry-leading strength, durability, and precision.

Our technical team is always on hand to help - contact us today for expert customized advice on your specific requirements.

Applications based on the flexural strength of ceramics

Semiconductor device carriers (alumina ceramics)

Application: Wafer support plates in deposition or etch chambers.
Reason: These sheets are subjected to repeated thermal cycling and mechanical loads.
Benefits: Ceramics have high flexural strength (~900-1000 MPa), excellent thermal shock resistance and dimensional stability.
Advantages: Prevent warping or cracking during high-temperature processing, improve device yield and process reliability, and extend service life in harsh environments.

High pressure pump plunger (zirconia ceramic)

Application: Plunger assemblies in pumps for abrasive or corrosive fluids
Cause: The plunger is subjected to cyclic bending and compression forces under high pressure.
Benefits: SSiC has a flexural strength of approximately 800-1000 MPa and excellent corrosion resistance.
Advantages: no deformation or fracture under mechanical loads, excellent performance in corrosive chemical environments, low maintenance costs, long service life

Ceramic ball bearings (silicon nitride Si₃N₄)

Application: Hybrid ceramic ball bearings
Reason: The ball is subjected to radial loads, centrifugal forces and micro-vibrations during operation.
Material Advantage: Silicon Nitride is lightweight and offers excellent strength and fatigue resistance.
Advantages: higher speeds, no thermal deformation, longer service life compared to steel bearings, operates without lubrication in vacuum or at high temperatures.

LED bases and thermal management substrates (aluminum nitride)

Applications: High Power LED Substrates and Chip Carriers
Reason: Thin ceramic substrates must resist mechanical bending and thermal stress.
Advantages: AlN has a flexural strength of about 300-400 MPa and a thermal conductivity >170 W/m-K.
Benefits: Maintains structural integrity under thermal cycling, supports power device miniaturization, enables efficient heat dissipation, and provides long-term reliability.

High-voltage insulator bracket (aluminum oxide 0)

Application: insulated poles and structural supports for substations
Reason: Mechanical loads from wind, cables and environmental stresses require high stiffness.
Benefits: Aluminum oxide ceramics offer reliable strength (300-450 MPa) and long-term outdoor durability.
Advantages: reliable support structure for electrical components, minimizes aging in outdoor conditions, excellent mechanical and dielectric properties

High-speed rail brake pads (ZTA ceramic)

Application: Ceramic Friction Elements in Braking Systems
Reason: Brake pads must resist shear and bending forces during repeated thermal cycling.
Benefits: ZTA (Zirconia Toughened Alumina) has enhanced toughness and flexural strength (~600-800 MPa).
Advantages: increased wear resistance, longer service life compared to metal systems, increased safety in extreme braking conditions.

Support arms for medical devices (glass ceramics can be processed)

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