16*12 Pressureless Sintered SiC Roller Long Service Life

Pressureless Sintered Silicon Carbide (SSiC) roller rods are advanced ceramic components manufactured from high-purity, ultrafine SiC powders with suitable sintering aids, through a solid-state or liquid-phase sintering process at elevated temperatures under normal atmospheric pressure. The resulting material contains ≥99% SiC, with a density ≥3.10 g/cm³ and virtually no free metallic impurities such as metallic silicon.

The 16 mm outer diameter and 12 mm inner diameter specification represents a precision small-bore SSiC roller rod with a wall thickness of only 2 mm. This geometry imposes extremely high demands on forming, sintering control, and post-machining. Such rods are typically produced by isostatic pressing or precision extrusion to meet the stringent dimensional accuracy and performance consistency required in high-temperature roller hearth kilns and precision drive systems.

The three mainstream processes for SiC roller rods – Reaction-Bonded (SiSiC), Pressureless Sintered (SSiC), and Recrystallized (RSiC) – are compared below:

SSiC outperforms reaction-bonded materials comprehensively in high-temperature strength, purity, corrosion resistance, and service life, making it the preferred choice for premium applications.

For the 16 mm OD * 12 mm ID SSiC roller rod, the typical properties are as follows:

SSiC roller rods contain no metallic silicon or other free metal phases. This is particularly critical in aggressive atmospheres such as lithium-ion battery cathode material sintering, where the 8–15% free silicon in reaction-bonded products is susceptible to corrosion by high-temperature alkaline environments, leading to premature failure. SSiC inherently eliminates this failure mechanism.

SSiC exhibits a flexural strength of 400 MPa at 1200°C – higher than at room temperature. This unusual strength retention, combined with a high elastic modulus of 420 GPa, ensures excellent creep resistance and minimal bending deformation under sustained high-temperature loads. Even with a thin wall of 2 mm, the 16 mm OD rod maintains sufficient rigidity and load-bearing capacity.

Pressureless sintered silicon carbide is inert to both strong acids and strong alkalis, outperforming tungsten carbide and alumina in chemical resistance. It demonstrates outstanding stability in kiln atmospheres containing fluorine, alkali, and other corrosive species.

With a thermal conductivity of 74 W/(m·K) at 1000°C – far higher than traditional ceramics like alumina – and a low thermal expansion coefficient of 4.1*10⁻⁶/K, SSiC rods enable rapid and uniform temperature distribution within the kiln. This prevents local hot spots, improves product quality, and reduces energy consumption by 10–20%.

Under identical operating conditions, the service life of SSiC roller rods is approximately 5* that of reaction-bonded SiSiC, 10* that of silicon nitride-bonded silicon carbide, and 15* that of recrystallized SiC.

The 16 mm OD * 12 mm ID SSiC roller rod is designed for precision high-temperature applications, including:

• Lithium-ion battery cathode sintering – used in roller hearth/pusher kilns for LiFePO₄ (LFP), NCM (nickel-cobalt-manganese), and LCO (lithium cobalt oxide) at high-temperature zones. The high-purity, metal-free system prevents metallic contamination of cathode materials.
• Electronic ceramics and MLCC sintering – for firing electronic substrates, magnetic materials, and multilayer ceramic capacitors (MLCCs) with tight tolerances.
• Semiconductor industry – employed in diffusion furnaces and other ultra-clean environments, where SSiC purity >99.9% meets stringent cleanliness requirements.
• Advanced and functional ceramics – for high-temperature firing of structural and functional ceramic components.

When specifying 16 mm OD * 12 mm ID SSiC roller rods, the following quality parameters should be given special attention:

This small-diameter precision product requires a manufacturer with proven capabilities in isostatic pressing or precision extrusion, and the ability to perform end machining (internal/external) to customer drawings. It is strongly recommended to request third-party test reports (e.g., from SGS) for density, flexural strength, thermal shock resistance, and other critical properties.

The 16 mm OD * 12 mm ID pressureless sintered silicon carbide roller rod, with its high-purity metal-free composition, outstanding high-temperature strength, superior corrosion resistance, and exceptionally long service life, is the ideal conveying and support component for precision high-temperature roller hearth kilns, lithium-ion battery material processing, and electronic ceramic sintering. Its thin-wall (2 mm) design demands sophisticated forming and sintering expertise; therefore, users should partner with established manufacturers that possess mature isostatic or extrusion technologies and comprehensive quality control systems to ensure reliable long-term performance under the most demanding operating conditions.