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Engineering Guide · 7 Materials · Grade Selection
Grade Guide

Ceramic grade selection —
the engineer's quick-reference.

Across our 7 ceramic materials, we offer 25+ production grades covering different purity levels, sintering routes, and application-specific optimizations. This guide explains what each grade is optimized for and gives you a quick decision framework — so you spec the right grade the first time and don't pay for performance you don't need.

7
Materials
25+
Grades
48h
DFM Reply
Free
Spec Review
Certifications & Standards
ISO 9001IATF 16949CERoHS · REACHUL Recognized
01 · Why Grade Selection Matters

One material, multiple recipes.

When buyers spec "silicon nitride" or "alumina" on a drawing, they usually have no idea that the same material name covers 3–5 different production grades, each optimized for a different application family and priced 30–200% apart. Picking the right grade for your duty profile is the single biggest cost-optimization lever on a ceramic specification.

MaterialUnitGrade CountPrice RangeMost-Used Grade
Silicon Nitride (Si₃N₄)grades41× to 3×Igniter Grade (BLK)
Alumina (Al₂O₃)purity31× to 4×99% Engineering
Zirconia (ZrO₂)variants31× to 1.5×Y-TZP (default)
Silicon Carbide (SiC)routes31× to 10×SSiC (default)
Aluminum Nitride (AlN)forms31× to 5×Standard substrate
Boron Carbide (B₄C)routes31× to 2×Hot-Pressed (armor)
Boron Nitride (BN)types21× to 5×h-BN (default)
Price range shows the multiplier from cheapest to most expensive grade within each material family. CVD-SiC's 10× premium reflects its semiconductor-grade purity vs SSiC.
02 · Material-by-Material Grade Guide

Grade decision trees.

Below are the standard grade picks for each material, with the duty-profile question that determines the choice. If your application doesn't fit any of these, contact our engineering team — most "edge case" specs we see are actually one of these standard grades plus a custom finishing step.

🔥
Si₃N₄ — 4 Grades

Standard: general structural. HIP-Processed: precision balls G3–G5. Igniter Grade (BLK): 100K+ thermal cycle. Cutting Grade: high-speed machining inserts. Most customers want Standard or Igniter Grade — HIP is reserved for aerospace bearings.

Decision → Cycling? BLK / Bearing? HIP / Otherwise? Standard
⚙️
Al₂O₃ — 3 Purity Grades

95%: industrial wear, grinding media, low-V insulators. 99%: engineering default — heating rods, thermocouple sheaths. 99.7%: semiconductor wafer fixtures, lab crucibles, spectral analysis tubes. Most customers want 99%.

Decision → Wafer/spectral? 99.7% / Wear? 95% / Otherwise? 99%
💎
ZrO₂ — 3 Variants

Y-TZP: default — biomed, cutting tools, balls. Mg-PSZ: higher service temp (1400°C). Ce-TZP: better wet/steam resistance. 90% of orders go to Y-TZP. Mg-PSZ for extrusion dies, Ce-TZP for steam-cycled environments.

Decision → Steam? Ce-TZP / 1000°C+ ? Mg-PSZ / Otherwise? Y-TZP
SiC — 3 Sintering Routes

SSiC (Pressureless): default — pump seals, structural. RBSiC (Reaction-Bonded): lower cost, complex shapes, kiln furniture. CVD-SiC: semiconductor purity (10× cost). Most customers want SSiC; RBSiC only for kiln furniture; CVD-SiC only for wafer fab.

Decision → Wafer fab? CVD / Kiln furniture? RBSiC / Otherwise? SSiC
💻
AlN — 3 Forms

Standard: 170 W/m·K, most heater and substrate applications. High-K: 200 W/m·K, power-density-critical electronics. DBC/DBA-Metallized: pre-bonded copper or aluminum for direct power module assembly. Standard covers 70% of orders.

Decision → Power module? DBC / Max thermal? High-K / Otherwise? Standard
🛡️
B₄C — 3 Routes

Hot-Pressed: armor tiles, high-density. Pressureless Sintered: lower cost, complex shapes. Reaction-Bonded: cost-effective for wear applications. Armor work always uses Hot-Pressed (98%+ density required).

Decision → Armor? Hot-Pressed / Wear? RBBC / Complex shape? PLS
📐
BN — 2 Types

Hot-Pressed h-BN: machinable, general crucibles and machined parts. Pyrolytic (PBN): ultra-pure, anisotropic thermal, semiconductor plasma chambers (3–5× h-BN cost). Use h-BN unless your application is semiconductor or aerospace insulator.

Decision → Plasma chamber? PBN / Otherwise? h-BN
🚀
Not Sure? Submit Drawing

If you're not sure which grade fits — that's fine, most customers aren't. Send your drawing and a description of your duty profile (temperature, cycles, environment). We'll recommend the right grade within 48 hours, with our reasoning.

Action → engineering@ceramitell.com
03 · The 3 Grade-Selection Rules

Quick rules that always work.

If you don't have time to read the full guide, these three rules cover 80% of grade decisions correctly. Apply them in order.

The 3 Rules

★ Quick-Pick
  • Rule 1: Start with the cheapest grade that meets your spec. Don't over-spec. Most failures we see come from buyers over-spec'ing because they want margin — but the price difference is real, and the lower grade usually works.
  • Rule 2: If the application thermally cycles, jump to Si₃N₄ or Igniter Grade. No matter what alumina spec sheet says about cycle life, in real thermal cycling, Si₃N₄ is the reliable choice past 50K cycles.
  • Rule 3: For semiconductor and aerospace, never go below the second-highest purity grade. Lot-to-lot contamination control matters more than the spec sheet shows. We've seen this for Al₂O₃ (99.7% required), SiC (CVD), and BN (PBN) applications.

Edge Cases We See

Custom needed
  • "Pharmaceutical grade" — Usually means USP <88> Class VI biocompatibility. Available for Y-TZP and 99.7% Al₂O₃.
  • "Food grade" — FDA-compatible Y-TZP available, primary market for chocolate refining and food powder grinding.
  • "Vacuum grade" — Means low outgassing for vacuum equipment. PBN and CVD-SiC are vacuum-default.
  • "Aerospace grade" — Usually means ITAR-aware supply chain + lot lineage. Available for Si₃N₄ structural and B₄C armor.
  • "Custom isotope" — B-10 enriched B₄C available for nuclear applications, requires export-license review.
★ Example · German Lab Equipment Manufacturer

From 99.7% spec to 99% — −35% material cost, same lab performance.

A German lab equipment manufacturer was spec'ing 99.7% alumina for all their lab tube furnace components. After DFM review of their actual operating spec (1200°C lab service, no plasma or wafer contact), we recommended 99% engineering grade for everything except the spectral analysis tubes. Material cost dropped 35% across the product line with no measurable performance change. They've expanded the right-sizing exercise across their full ceramic component bill of materials.

Right-Sized Grade
99.7% → 99% outcome
  • −35% Material cost
  • Same Lab performance
  • Same Lead time
  • Free Grade review by our team