Alumina Ceramic Disc (Al₂O₃) for High-Temperature Insulation & Precision Fixturing

Alumina Ceramic Disc Applications

• Laboratory Ashing & High-Temp Sample Support

  ✅Key Advantages

  1. Stable up to typical lab furnace ranges (≤1500–1600 °C), minimizing warpage in repeated cycles.
  2. Flat, clean surfaces reduce contamination and keep sample contact uniform.
  3. Rigid, non-conductive support prevents current paths inside heated fixtures.

  ✅ Problem Solved

  Switching to a 99.7% alumina disc with flatness ≤0.1 mm/100 mm cut re-runs by 18% over one quarter because samples no longer slid or tipped at temperature; breakage claims dropped to <2% after edge-radius adoption and improved packaging.

• High-Voltage Electrical Insulation & Isolation

  ✅Key Advantages

  1. High dielectric strength (typically >10 kV/mm, thickness-dependent) reduces leakage risk.
  2. Low CTE drift (≈7–8×10⁻⁶/K) maintains clamping force across heat cycles.
  3. Machinable holes/slots allow secure fastening without metallic shims.

  ✅ Problem Solved

  After replacing laminated spacers with alumina discs of controlled thickness ±0.10 mm, leakage events during hipot dropped from 3/1000 units to <1/1000 and torque re-checks per batch decreased by 30% due to thermal stability.

• Industry Precision Fixturing / Lapping & Polishing Support

  ✅Key Advantages

  1. Hard, wear-resistant contact resists slurry abrasion in lapping lines.
  2. Double-sided ground/one-sided polished options hold parallelism for even pressure.
  3. Laser-ID enables disc rotation tracking to analyze wear patterns.

  ✅ Problem Solved

  A polishing cell using discs with specified parallelism ≤0.02 mm and matte + polished combo surface improved thickness uniformity by 12% and reduced pad change frequency by 1 cycle/week, saving ~8 hours monthly.

Alumina Ceramic Discs Usage Instructions

• Use

  1. Mount discs on clean, flat support surfaces to avoid rocking and uneven loading.
  2. Prevent point loading on thin discs; distribute load with smooth plates or compliant pads.
  3. Always re-check clamp torque after the first heat cycle, since initial shrink-fit or bow correction can shift load balance.
  4. For electrical insulation uses, verify that disc edges are free of micro-chips before assembly.

• Storage

  1. Keep in sealed, dry bags with desiccant packs to prevent moisture absorption that could lower dielectric strength.
  2. Use interlayers (foam, soft paper, or plastic films) to prevent edge-to-edge contact.
  3. Store vertically on edge racks for discs thinner than 1 mm to minimize bowing or creep.
  4. Maintain storage areas below 40% relative humidity, away from corrosive vapors or vibration.

• Cleaning

  1. Use non-metallic tools to avoid scratching or introducing conductive particles.
  2. Suitable methods: mild ultrasonic cleaning, isopropanol or ethanol wipe, or DI-water rinse with quick dry.
  3. Avoid hydrofluoric acid or strong alkalis (NaOH, KOH) that chemically attack Al₂O₃.
  4. After cleaning, handle discs with powder-free gloves to prevent finger oils that may cause hot spots or leakage.

• Common mistakes & fixes

  1. Edge chipping during handling → specify discs with chamfer or radius; handle with trays or vacuum pick-up tools.
  2. Uneven heating marks → confirm required flatness grade (e.g., ≤0.1 mm/100 mm) and ensure uniform support; avoid three-point clamping that causes hot spots.
  3. Electrical leakage spikes → check for surface moisture or contamination; pre-bake at 150–200 °C to remove absorbed water before hipot testing.
  4. Warping of thin discs → store vertically and clamp evenly; for long cycles above 1200 °C, specify reinforced support or lower bow tolerance.
  5. Surface contamination during polishing → cover discs with protective film until ready for use; request clean-room level packaging if used in sensitive assemblies.

Alumina Ceramic Discs FAQ

1. What is the melting point of an alumina disc?
   The intrinsic melting point of alumina is ~2050 °C; for long-term service, discs are commonly specified for ≤1500–1600 °C depending on size and finish.
2. What are the thermal properties I should know?
   Coefficient of thermal expansion is about 7–8×10⁻⁶/K; thermal conductivity is moderate and stable with temperature compared with glass or mica laminates.
3. Is alumina disc transmittance relevant?
   Dense alumina is opaque/low-transmittance in visible light; if optical transmission is required, specify thickness and wavelength so we can advise feasibility or alternatives.
4. Do you supply alumina discs for sale from stock?
   Yes—common ODs and thicknesses are stocked for fast shipment; thin or ultra-flat formats are made to order.
5. Q: Do you manufacture alumina ceramic discs in China?
   A: Yes. ADCERAX produces alumina ceramic discs at our factory in China. We supply both standard 99.5%–99.7% Al₂O₃ discs and custom-made designs based on drawings or samples. Each batch is checked for tolerance, flatness, and surface quality, and packaged clean for export. This way, buyers can source factory-direct alumina ceramic discs from China with reliable quality and stable lead times.
6. Q: What purity should I choose—alumina disc 99.5 or 99.7?
   A: The choice depends on your application. 99.5% alumina discs are suitable for most general uses such as insulation, ashing, and routine high-temperature support. If your process requires tighter stability, lower contamination, or more consistent dielectric performance, 99.7% alumina discs are recommended. ADCERAX can provide both grades and help you compare options based on your technical needs and budget.

What Our Customers Say about Alumina Ceramic Disc

• ⭐️⭐️⭐️⭐️⭐️
  “We switched to alumina ceramic discs with controlled flatness, and hipot leakage problems disappeared. Reorders matched our drawings and required no extra qualification.”
  -- Maria V., Process Engineer, VoltGrid Power
• ⭐️⭐️⭐️⭐️⭐️
  “Stock alumina discs for sale covered our routine ashing work. Thin custom discs with edge radius reduced chipping, and batch labels made tracking easier.”
  -- Kenji T., Lab Manager, Seikaku Materials
  
• ⭐️⭐️⭐️⭐️⭐️
  “The 99.5% Al₂O₃ disc kept thickness consistent across cycles, improving clamp repeatability. Holes and chamfers were accurate, which shortened assembly time.”
  -- Ethan G., Operations, Northbridge Instruments
  
• ⭐️⭐️⭐️⭐️⭐️
  “For our quarterly build, the wholesale alumina discs from ADCERAX arrived in clean packs with stable flatness, ensuring fixture pressures stayed uniform.”
  -- Lena M., Buyer, EuroTech Controls