AlN
AlN is a sintered aluminium nitride ceramic covered by GB/T 38967, electrically insulating while conducting heat at 180 W/m·K, normally densified with a Y2O3 sintering aid.
Reference datasheet — AlN is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the AlN-180 condition
AlN tempers and conditions
AlN is supplied in 5 conditions, soft to hard. AlN-180 is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Machinable AlN–BN composite | Pick when parts must be turned/milled with carbide tooling after firing and moderate thermal conductivity is acceptable. | 400 HV | 70 W/m·K | |||
AlN-180Default Pressureless-sintered high thermal conductivity substrate grade | Standard commercial power-electronics substrate/heat-spreader grade; pick when maximum heat spreading with full dielectric isolation is needed. | 1,100 HV | 180 W/m·K | |||
High-resistance grade | Choose when insulation resistance must stay high at elevated temperature or under DC bias (ESC bodies, HV isolators, high-voltage power modules). | 1,100 HV | 150 W/m·K | |||
Microwave-lossy AlN composite | Choose for TWT/klystron RF attenuators, terminations and absorber rods needing high dielectric loss plus AlN-level heat removal. | 1,150 HV | 80 W/m·K | |||
Pressure (hot-pressed / HIP) sintered aluminium nitride | Use for near-zero-porosity, highest-strength AlN parts and large blanks where an isotropic, fully dense body matters more than substrate cost. | 1,200 HV | 160 W/m·K |
What is AlN?
AlN is a sintered aluminium nitride ceramic covered by GB/T 38967, electrically insulating while conducting heat at 180 W/m·K, normally densified with a Y2O3 sintering aid. It is specified for power electronics substrates and heat spreaders where dielectric isolation and heat removal are both required, and is supplied as tape-cast substrates, pressed and hot-pressed blocks, metallized substrates and RF windows. Density is 3.26 g/cm3, elastic modulus 320 GPa and maximum service temperature 900 °C. It hydrolyses in hot water and alkaline media and costs more than alumina, which remains the alternative when thermal conductivity is not critical. AlN has a density of 3.26 g/cm³ (0.118 lb/in³), lighter than 70% of ceramic grades. It melts at 2,200°C (3,992 °F). AlN has a tensile strength of 200 MPa (29 ksi), stronger than 60% of ceramic grades. The elastic modulus is 320 GPa (46.4 Msi).
What is AlN used for?
- power electronics substrates
- LED heat sinks
- microwave device packaging
- RF windows
Advantages
- Conducts heat well — 180 W/m·K (104 BTU/hr·ft·°F), better than 96% of ceramic grades
AlN properties
Typical room-temperature values for AlN-AlN-180; bars are the position among ceramic grades.
Physical4
AlN has a density of 3.26 g/cm³ (0.118 lb/in³), lighter than 70% of ceramic grades. It melts at 2,200°C (3,992 °F).
Mechanical11
AlN has a tensile strength of 200 MPa (29 ksi), stronger than 60% of ceramic grades. The elastic modulus is 320 GPa (46.4 Msi).
Thermal5
AlN is rated for continuous service to 900°C (1,652 °F). It conducts heat at 180 W/m·K (104 BTU/hr·ft·°F), better than 96% of ceramic grades. Thermal expansion is 4.4 µm/m·K (2.44 µin/in·°F).
Electrical5
AlN is an electrical insulator with a dielectric strength of 17 kV/mm (431.8 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (85/100), better than 69% of ceramic grades.
Sustainability4
Producing a kilogram of AlN takes about 280 MJ of energy and emits 22 kg of CO₂ — more than 71% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
AlN's machinability is not recommended (5/100, worse than 59% of ceramic grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the ceramic family
Yield strength against density for every ceramic grade FabDigit runs. AlN is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AlN
Is AlN easy to machine?
Green/pre-sintered bodies can be milled or laser-scribed cheaply; fired AlN needs diamond grinding, lapping or laser/ultrasonic machining, and dry machining is preferred to limit surface hydrolysis.
Can AlN be welded?
Not weldable — joined by active-metal brazing (Ti/Ag-Cu-Ti), DBC/AMB copper bonding, glass frit or metallized (Mo-Mn/W) plus Ni-plated brazing.
Can AlN be formed, bent or molded?
Tape cast for substrates, dry/isostatic pressed or injection moulded for shapes, then debound and sintered ~1750–1850 °C in flowing N₂ with Y₂O₃ aid; allow ~17–20 % linear shrinkage.
AlN chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Nas AlN | 31 – 34.2 | 33 |
| Yadded as Y₂O₃ sintering aid (typ. 2–5 wt% Y₂O₃) | 0.8 – 3.5 | 2 |
| Olattice + grain-boundary oxygen; lower O = higher thermal conductivity | 0.3 – 2 | 1 |
| Cresidual from carbothermal powder | ≤ 0.15 | 0.05 |
| Albalance, ~65 wt% | balance |
What surface finishes work on AlN?
Lapped/polished to Ra <0.05 µm for substrates; thin-film Ti/Ni/Au sputtering, thick-film W/Mo-Mn metallization, DBC or AMB copper are standard; avoid prolonged exposure to hot water or alkaline cleaners.
Equivalent designations
Standards and trade names that resolve to AlN in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- GB/T 38967
How much does AlN cost?
AlN is a high-cost ceramic ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
AlN — frequently asked
What is AlN used for?
AlN is typically used for power electronics substrates, LED heat sinks, microwave device packaging and RF windows. In short: 180 W/m·K dielectric ceramic; power substrate standard; costlier than alumina.
What is the tensile strength of AlN?
AlN has a typical tensile strength of 200 MPa (29 ksi) — stronger than 60% of ceramic grades. Strength varies by condition: see the 5 listed tempers.
Is AlN easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 59% of ceramic grades). Green/pre-sintered bodies can be milled or laser-scribed cheaply; fired AlN needs diamond grinding, lapping or laser/ultrasonic machining, and dry machining is preferred to limit surface hydrolysis.
Can AlN be welded?
Not weldable — joined by active-metal brazing (Ti/Ag-Cu-Ti), DBC/AMB copper bonding, glass frit or metallized (Mo-Mn/W) plus Ni-plated brazing.
What surface finishes work on AlN?
Lapped/polished to Ra <0.05 µm for substrates; thin-film Ti/Ni/Au sputtering, thick-film W/Mo-Mn metallization, DBC or AMB copper are standard; avoid prolonged exposure to hot water or alkaline cleaners.
Can AlN be formed, bent or molded?
Tape cast for substrates, dry/isostatic pressed or injection moulded for shapes, then debound and sintered ~1750–1850 °C in flowing N₂ with Y₂O₃ aid; allow ~17–20 % linear shrinkage.
What is the maximum service temperature of AlN?
AlN is rated for continuous use to about 900°C (1,652 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does AlN cost?
AlN is a high-cost ceramic ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASM Engineered Materials Handbook, Vol. 4: Ceramics and Glasses — ASM International (1991)
- Aluminum Nitride (AlN) technical ceramic datasheets — CoorsTek / Kyocera / CeramTec / Maruwa (2023)
- MatWeb / Ceramic property tables for AlN — MatWeb LLC (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.