Silicon Nitride Ceramic Block for High-Temperature Industrial Equipment

Applications of Silicon Nitride Blocks

• Heat Treatment Furnaces and Kiln Fixtures

  ✅Key Advantages

  1. Consistent support strength close to 1000°C, reducing fixture deformation in continuous furnaces.
  2. Low thermal expansion (~3×10⁻⁶/K) helps maintain stack height and alignment across many cycles.
  3. Thermal shock resistance in the 600–700°C differential range supports fast heating or quenching sequences.

  ✅ Problem Solved

  A heat treatment OEM designing a multi-layer fixture for automotive parts needs support blocks that do not deform or crack after repeated 800–950°C cycles. Conventional alloy support pieces show permanent distortion and require replacement after a limited number of cycles. By using silicon nitride ceramic blocks sized to carry the same load, the fixture maintains flatness over many more cycles thanks to higher high-temperature strength, lower creep and better thermal shock resistance. This reduces fixture rework and keeps part geometry within specification across longer production runs.

• Aluminum Casting and Foundry Cells

  ✅Key Advantages

  1. Good resistance to wetting and chemical attack by molten aluminum compared with many steel or basic refractory blocks.
  2. Stable strength at operating temperatures, supporting launders, weirs or covers with less mass loss over time.
  3. Low thermal expansion and thermal shock resistance improve resistance to temperature cycling when the line starts and stops.

  ✅ Problem Solved

  In an aluminum casting cell, metal-contact blocks made from traditional refractory or steel gradually erode, build oxide deposits and need frequent replacement. Each replacement causes an interruption and brings a risk of dimensional changes in the metal flow path. Switching to silicon nitride ceramic blocks reduces wetting and erosion at typical aluminum casting temperatures and keeps contact surfaces stable across more campaigns. The result is steadier metal flow, fewer adjustments and fewer unplanned interventions for block replacement.

• Metal Forming and Grinding Equipment

  ✅Key Advantages

  1. High flexural strength and fracture toughness help blocks resist chipping under contact with workpieces or tooling.
  2. High hardness and wear resistance improve life in abrasive contact, reducing replacement intervals in guides and stops.
  3. Dimensional stability in elevated temperature or coolant environments maintains alignment and part quality.

  ✅ Problem Solved

  A metal forming line uses hardened steel blocks as guides and stops near a heated zone. Over time, abrasive contact with scale and repeated thermal cycling cause rounding of edges and micro-cracking, which gradually shifts the forming position. By replacing those guides with silicon nitride ceramic blocks machined to the same profile, the line benefits from higher hardness and better thermal shock resistance. The guides keep their geometry for longer periods, reducing setup time and scrap from misaligned forming.

Si3N4 Ceramic Block Usage Instructions

• Installation

  1. Check support and mounting surfaces
  Ensure that the steel frame or refractory bed supporting the silicon nitride ceramic block is flat, rigid and free from burrs or loose particles that could create high local stresses.
  2. Avoid point loading
  Design contact areas so that loads are distributed over sufficient area. Where necessary, use intermediate pads or shims to reduce concentrated forces on sharp corners.
  3. Control clamping pressure
  If clamps or fasteners are used, apply torque evenly and avoid over-tightening, which can introduce bending stress into the block.

• Use in Operation

  1. Respect temperature gradients
  Silicon nitride ceramic blocks tolerate rapid cycling, but extreme local gradients should still be minimized by gradual ramp-up or controlled burner placement.
  2. Avoid mechanical shock
  Do not strike the blocks with hammers or tools during installation or maintenance. Use lifting aids or padded supports when moving heavy blocks.
  3. Monitor for process changes
  If loads, cycle times or temperatures change significantly, review block dimensions and support design to confirm they are still adequate.

• Storage

  1. Store blocks in dry, clean indoor areas away from corrosive chemicals or impact hazards.
  2. Place blocks on pallets or shelves with soft pads between parts to avoid edge contact.
  3. Clearly label sizes and part numbers to reduce handling and sorting.

• Cleaning and Inspection

  1. After service, allow blocks to cool gradually to room temperature before handling.
  2. Remove loose scale or deposits with soft brushes or non-metallic tools.
  3. For fixtures with tight tolerances, measure key surfaces periodically to track wear or impact marks.

• Common Misuse Points and Mitigation

  1. Problem: Mounting the silicon nitride ceramic block directly onto an uneven metal frame, causing localized bending.
  Solution: Shim or machine the support surface to improve flatness, and re-check contact with feeler gauges or blueing.

  2. Problem: Using the block as a lever point or step during maintenance work.
  Solution: Define clear rules that blocks are functional components, not walkways or lifting points, and provide separate access platforms.

  3. Problem: Rapid water quenching from very high temperature beyond design limits.
  Solution: Follow process-specific cooling procedures; if emergency quenching can occur, discuss safety margins and geometry with engineering support before installation.

Silicon Nitride Ceramic Block FAQ

1. Q: How does a Si3N4 ceramic block differ from an alumina block?
   A: Compared with typical alumina blocks, a silicon nitride ceramic block offers higher fracture toughness, lower thermal expansion and better thermal shock resistance, which gives it a higher tolerance for rapid temperature changes and mechanical shock.
2. Q: What temperature can a silicon nitride ceramic block withstand in service?
   A: For many sintered silicon nitride grades, maximum working temperatures in air are typically around 1000–1200°C under moderate load; the exact limit depends on the grade and component geometry.
3. Q: Can you supply custom silicon nitride ceramic blocks from drawings or samples?
   A: Yes. Custom silicon nitride ceramic blocks can be machined from standard plates or near-net-shape blanks according to customer drawings or existing samples, including holes, slots and stepped profiles.
4. Q: What tolerances are typical for Si3N4 ceramic blocks?
   A: For many industrial fixtures, silicon nitride ceramic blocks can be ground to general dimensional tolerances on the order of ±0.05–0.10 mm and controlled flatness and parallelism appropriate for the fixture layout, depending on block size and machining allowance.
5. Q: Where are silicon nitride ceramic blocks commonly used?
   A: They are widely used in furnace fixtures for heat treatment, aluminum casting and foundry cells, high-temperature jigs, metal forming lines, grinding equipment and other areas where high-temperature strength and wear resistance are required.
6. Q: Are silicon nitride ceramic blocks suitable for contact with molten aluminum?
   A: Yes. Silicon nitride ceramic blocks are used in aluminum casting equipment because of their resistance to wetting and chemical attack by molten aluminum, combined with thermal shock resistance during start–stop cycles.

Customer Reviews — Silicon Nitride Ceramic Blocks

• ⭐️⭐️⭐️⭐️⭐️
  We replaced steel support pieces in a batch furnace with silicon nitride ceramic blocks from ADCERAX. The new blocks hold their shape much better at 900°C, and fixture adjustments between campaigns have dropped significantly
  -- Whitney Romero (Engineer)
• ⭐️⭐️⭐️⭐️⭐️
  Custom Si3N4 ceramic blocks in our casting launders have reduced buildup and erosion compared with the previous refractory blocks. The service interval is longer, and we spend less time rebuilding these sections during planned shutdowns.
  -- Ayoub (Purchasing Manager)
• ⭐️⭐️⭐️⭐️⭐️
  We use silicon nitride structural blocks as guides and stops in several forming lines. After months of operation, the edges are still sharp, and we have not seen the typical wear patterns we had with hardened steel components.
  -- Ayoub (Purchasing Manager)
• ⭐️⭐️⭐️⭐️⭐️
  For our heat treatment fixtures, ADCERAX supplied machined silicon nitride ceramic blocks directly from our CAD files. The dimensional consistency has been good, and the lead time for repeat orders fits well with our project schedule.
  -- Ayoub (Purchasing Manager)