Silicon Nitride Plate (Sheet) — Precision Ground Plates for Heat-Cycle, Non-Wetting and Wear Applications

Silicon Nitride Reaction-Bonded Sheet Application

• Molten Aluminum Casting & Foundry Cells

  ✅Key Advantages

  1.  Non-Wetting Contact Surface — reduces aluminum buildup and post-run scraping time per shift.
  2. Flatness Stability — maintains parallel gaps in launders/gates after repeated heat cycles.
  3. Edge Integrity — drilled holes and slots resist micro-chipping during fixture changes.

  ✅ Problem Solved

  A die-casting cell replaced metallic inserts with silicon nitride plates on aluminum-contact surfaces. Buildup removal time per 8-hour shift fell from ~25 min to ~7 min; fixture re-alignment events dropped from 3 to 1 per week due to better flatness retention, adding ~1.5–2.0 % weekly uptime. The line subsequently standardized plate geometry to enable interchangeable spares across molds.

• Heat-Treatment & Industrial Furnace Fixtures

  ✅Key Advantages

  1. Low CTE Plate — reduces thermal-cycle warpage and maintains hole-to-slot alignment.
  2. Ground Surface — stable Ra enhances part support and lowers imprint risk.
  3. Repeatable Tolerance Window — supports fixture interchange across multiple lines.

  ✅ Problem Solved

  A job shop processing tool steels moved to ground Si₃N₄ setter plates (200×200×6 mm, flatness ≤0.1 mm/100 mm). After 500+ cycles, plate deformation stayed within ≤0.12 mm; re-shimming frequency dropped by 60 %, cutting changeover labor ~30–40 min per batch.

• Mining, Aggregates & Bulk Handling (Wear Surfaces)

  ✅Key Advantages

  1. High Hardness Plate — resists sliding abrasion on chutes and transfer points.
  2. Corner/Edge Engineering — chamfers prevent crack initiation under impact.
  3. Thickness Control — maintains target standoff to protect adjacent structures.

  ✅ Problem Solved

  On a limestone line, replacing alloy wear plates with Si₃N₄ wear plates extended change intervals from 6 to 14 weeks. Maintenance windows consolidated from bi-monthly to quarterly, lowering spare usage and unplanned downtime by ~18 hours per quarter.

Silicon Nitride Ceramic Plate Usage Instructions

• Installation

  1. Verify plate flatness and thickness against the technical drawing using a calibrated gauge before mounting. Dry-fit the plate on locating pins to confirm alignment.
  2. Apply torque-limited fasteners and uniform pressure during installation. Avoid concentrated loads at unsupported corners or edges that can cause tensile stress and micro-cracks.
  3. For aluminum contact environments, ensure all mating metallic surfaces are clean and free of oxidation or burrs; metallic smears can act as bonding points and increase aluminum adhesion over time.
  4. If using adhesives or thermal interface layers, select materials with similar thermal expansion coefficients (CTE 2.5–3.2×10⁻⁶/K) to prevent interfacial stress.

• In Service

  1. Follow the controlled heat-up and cool-down ramp specified for your furnace or fixture to minimize thermal shock. Rapid transitions beyond ±200 °C/min may exceed Si₃N₄’s allowable gradient.
  2. Keep abrasive fines and debris off ground surfaces. Periodically wipe the plate with lint-free, non-abrasive cloths to avoid third-body wear that gradually increases Ra and reduces flatness.
  3. Inspect hole and slot clearances every 500–1000 operating hours. If positional wear exceeds tolerance (≥0.1 mm shift), replace the plate or ream fixture pins to avoid misalignment.
  4. In molten aluminum service, rotate or flip plates periodically to distribute heat exposure evenly, extending service life.

• Storage

  1. Store plates horizontally on flat trays or pallets with foam or polymer face separators to prevent face-to-face abrasion.
  2. Avoid vertical leaning on edges, which can concentrate static loads and create corner stress.
  3. Keep in a dry, temperature-stable environment (humidity ≤60 %), and avoid large temperature swings that cause condensation or thermal gradients.
  4. For long-term storage, use vacuum-sealed bags with desiccant to prevent surface oxidation or contamination before assembly.

• Cleaning

  1. For aluminum-contact plates, start with a plastic scraper to remove surface residue; if required, use fine blasting media (≤50 μm alumina or glass beads) at <0.3 MPa air pressure to clean oxidation without eroding the glaze.
  2. For wear and support surfaces, wipe with alcohol or mild alkaline detergent, rinse with deionized water, and dry with warm air (<100 °C). Avoid steel brushes or aggressive abrasives that raise surface roughness above Ra 1.6 μm.
  3. After cleaning, inspect visually under 500 lux lighting for micro-cracks or edge defects before reuse.

• Common Misuse & Fixes

  1. Over-tightening screws at corners → micro-cracks
  Fix: Apply torque control (recommended 2–3 N·m for M4 clamps) and use load-spreading washers or soft gaskets to reduce point stress.

  2. Rapid quenching from high temperature → thermal shock cracks
  Fix: Implement staged cooling in furnace programs; maintain ≤200 °C/min ramp down. Avoid cold-air exposure immediately after furnace extraction.

  3. Improper stacking or transport → corner chipping
  Fix: Always use foam-corner protectors and flat support boards. Do not stack more than five plates per layer during handling or shipment.

Silicon Nitride Plate (Sheet) FAQ

1. Q: What makes a silicon nitride ceramic plate(sheet) different from common oxide ceramics?
   A: Silicon nitride plates combine high strength (≈600 MPa) with low thermal expansion (2.5–3.2 × 10⁻⁶/K), meaning they stay flat even after hundreds of heat cycles. Unlike alumina, which can warp or crack under rapid temperature changes, Si₃N₄ offers superior thermal-shock tolerance and edge toughness, making it ideal for precision jigs, heat-treatment setters, and aluminum-contact applications.
2. Q: How does a silicon nitride sheet prevent aluminum wetting and buildup?
   A: The covalent Si–N bonds and surface oxide film of Si₃N₄ generate low surface energy against molten aluminum. This causes droplets to bead rather than spread, effectively preventing chemical adhesion. In foundry environments, non-wetting behavior can reduce cleaning downtime by 60–70 % and extend replacement intervals.
3. Q: What are the recommended flatness and surface finish levels for Si₃N₄ plates used in fixtures or furnace setters?
   A: For most industrial setups, flatness ≤ 0.10 mm/100 mm and parallelism ≤ 0.10 mm ensure reliable part support and heat uniformity. Ground surfaces typically reach Ra ≤ 1.6 µm, while optical or sealing surfaces may be polished to Ra ≤ 0.4 µm. Tighter tolerances are achievable on small-format plates.
4. Q: Can Si3N4 plates be customized with holes, slots, or complex profiles?
   A: Yes. The material can be diamond-machined to include through holes, countersinks, or pockets with positional tolerances of ±0.05–0.10 mm. Design reviews usually address minimum edge spacing (≥ 1.5 × hole Ø) and chamfering to prevent micro-cracks during assembly.

5. Q: How does silicon nitride compare to SiC or AlN plates for thermal and mechanical performance?
   A: a. Si₃N₄: Balanced toughness + thermal stability; best for shock and mechanical stress.
   b. SiC: Higher thermal conductivity but brittle under impact.
   c. AlN: Excellent thermal conduction but moisture-sensitive and costly.
   Thus, Si₃N₄ is often the preferred structural ceramic for repeated thermal cycling and mechanical loading.

6. Q: What information should be provided when requesting a quotation for silicon nitride plates?
   A: Include L × W × T dimensions, tolerance targets, surface finish (Ra), flatness requirement, hole/slot layout, edge radius or chamfer details, and intended application (e.g., molten aluminum contact, furnace setter, wear plate). Drawings in STEP, DWG, or PDF formats enable accurate cost and lead-time evaluation.

Silicon Nitride Ceramic Plate /Sheet Reviews

• ⭐️⭐️⭐️⭐️⭐️
  We purchased several silicon nitride plates for use as precision support bases in our heat-treatment jigs. The flatness and dimensional repeatability were excellent — within ±0.05 mm across 250 mm size. After 400+ cycles, no visible deformation or surface pitting occurred. These Si₃N₄ plates outperform alumina parts we used before, especially in maintaining alignment during thermal cycling.
  -- Markus R., Process Engineer, ThermoForm GmbH
• ⭐️⭐️⭐️⭐️⭐️
  Our team replaced graphite liners with sintered silicon nitride ceramic sheets supplied by ADCERAX. The non-wetting surface against molten aluminum significantly reduced cleaning frequency and dross adhesion. Even after 900 casting runs, the plates remained dimensionally stable and easy to clean. They’ve become a core part of our foundry tooling.
  -- Jonathan K., Maintenance Supervisor, AluCast Systems Inc.
• ⭐️⭐️⭐️⭐️⭐️
  For our vacuum furnace project, we selected reaction bonded silicon nitride sheets because they offer a lighter structure with sufficient thermal-shock resistance. The finish quality was uniform, and delivery included full inspection data. Compared with sintered types, these silicon nitride reaction bonded sheets are cost-effective for non-load-bearing thermal shields.
  -- Dr. Ayumi Tanaka, Materials Scientist, Kyowa LabTech
• ⭐️⭐️⭐️⭐️⭐️
  ADCERAX customized a batch of silicon nitride – reaction bonded sheets and thicker silicon nitride plates with counterbored holes for our automation fixtures. Communication was smooth, and tolerances matched our CAD drawings perfectly. The combination of lightweight sheets and dense plates allowed us to optimize both cost and rigidity in our design.
  --Carlos E., Project Engineer, MechaSol Industrial S.L.