Alumina 99.5
also High Purity Alumina
Alumina 99.5 (F603) is a high-purity sintered Al₂O₃ structural ceramic, also available HIPed for maximum density.
Reference datasheet — Alumina 99.5 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 Sintered condition
Alumina 99.5 tempers and conditions
Alumina 99.5 is supplied in 2 conditions, soft to hard. Sintered is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SinteredDefault pressed and sintered (default) | Standard dry-pressed / isopressed and air-sintered 99.5 % alumina for insulators, tubes, wear and seal parts. | 260 | 1,650 HV | 32 W/m·K | ||
Hot isostatic pressed | Pick when maximum density, strength and plasma/vacuum performance are required — e.g. semiconductor chamber parts and highly loaded seal faces. | 320 | 1,900 HV | 35 W/m·K |
What is Alumina 99.5?
Alumina 99.5 (F603) is a high-purity sintered Al₂O₃ structural ceramic, also available HIPed for maximum density. It is specified for hardness, wear resistance, electrical insulation and chemical inertness (corrosion score 95), with 3.9 g/cm³ density, 260 MPa tensile strength, 372 GPa modulus, 32 W/m·K thermal conductivity and service to 1700 °C, supplied as pressed, extruded, cast or injection-moulded near-net shapes. It cannot be welded and, once fired, only diamond grinding or laser/waterjet processing works (machinability score 5), so tooling and lead time cost more than for 96 % alumina. Alumina 96 is the lower-cost substitute. Alumina 99.5 has a density of 3.9 g/cm³ (0.141 lb/in³), lighter than 58% of ceramic grades. It melts at 2,050°C (3,722 °F). Alumina 99.5 has a tensile strength of 260 MPa (37.7 ksi), stronger than 65% of ceramic grades. The elastic modulus is 372 GPa (54 Msi).
What is Alumina 99.5 used for?
- Semiconductor wafer carriers
- High-voltage insulators
- Vacuum feedthroughs and headers
- Seal faces and pump plungers
- Wear rings and nozzles
- Furnace tubes and fixtures
- RF and laser ceramic components
Advantages
- Good corrosion resistance — 95/100, better than 97% of ceramic grades
- High service temperature — 1,700°C (3,092 °F), better than 90% of ceramic grades
- Low embodied carbon — 3 kg CO₂/kg, better than 88% of ceramic grades
Alumina 99.5 properties
Typical room-temperature values for Alumina 99.5-Sintered; bars are the position among ceramic grades.
Physical4
Alumina 99.5 has a density of 3.9 g/cm³ (0.141 lb/in³), lighter than 58% of ceramic grades. It melts at 2,050°C (3,722 °F).
Mechanical12
Alumina 99.5 has a tensile strength of 260 MPa (37.7 ksi), stronger than 65% of ceramic grades. The elastic modulus is 372 GPa (54 Msi).
Thermal5
Alumina 99.5 is rated for continuous service to 1,700°C (3,092 °F). It conducts heat at 32 W/m·K (18.5 BTU/hr·ft·°F), better than 62% of ceramic grades. Thermal expansion is 7 µm/m·K (3.89 µin/in·°F).
Electrical5
Alumina 99.5 is an electrical insulator with a dielectric strength of 17 kV/mm (431.8 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (95/100), better than 97% of ceramic grades.
Sustainability4
Producing a kilogram of Alumina 99.5 takes about 52 MJ of energy and emits 3 kg of CO₂ — less than 81% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
Alumina 99.5'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. Alumina 99.5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Alumina 99.5
Is Alumina 99.5 easy to machine?
Green or bisque machine wherever possible; after firing only diamond grinding, lapping, ultrasonic or laser/waterjet cutting works — allow generous grinding stock and avoid sharp internal corners.
Can Alumina 99.5 be welded?
Not weldable; join by active-metal brazing (Ti/Ag-Cu), Mo-Mn metallization plus Ni plating and brazing, glass sealing or structural adhesive.
Can Alumina 99.5 be formed, bent or molded?
Formed as a green body by dry/isostatic pressing, extrusion, slip or injection casting, then sintered at ~1600–1700 °C with ~15–20 % linear shrinkage; HIP adds a second densification cycle.
Alumina 99.5 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 |
|---|---|---|
| SiO2sintering aid / impurity | ≤ 0.2 | 0.1 |
| MgOgrain-growth inhibitor | ≤ 0.15 | 0.08 |
| CaO | ≤ 0.1 | 0.04 |
| Na2Oalkali impurity, limited for HV insulators | ≤ 0.1 | 0.05 |
| Fe2O3 | ≤ 0.05 | 0.02 |
| Al2O3purity by weight after firing | ≥ 99.5 (balance) |
What surface finishes work on Alumina 99.5?
Lapping/polishing gives <0.05 µm Ra optical-grade faces; metallize (Mo-Mn or thin-film Ti/Pt/Au) for solderable/brazable surfaces; no plating or painting is needed for corrosion protection.
Equivalent designations
Standards and trade names that resolve to Alumina 99.5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- High Purity Alumina
- Also called
- Al2O3 99.5%
- Similar grades
- F6036474
How much does Alumina 99.5 cost?
Alumina 99.5 is a high-cost ceramic ($$$$), pricier than about 98% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Alumina 99.5 — frequently asked
What is Alumina 99.5 used for?
Alumina 99.5 is typically used for semiconductor wafer carriers, high-voltage insulators, vacuum feedthroughs and headers, seal faces and pump plungers, wear rings and nozzles and furnace tubes and fixtures. In short: premium high-purity alumina.
What is the tensile strength of Alumina 99.5?
Alumina 99.5 has a typical tensile strength of 260 MPa (37.7 ksi) — stronger than 65% of ceramic grades. Strength varies by condition: see the 2 listed tempers.
Is Alumina 99.5 easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 59% of ceramic grades). Green or bisque machine wherever possible; after firing only diamond grinding, lapping, ultrasonic or laser/waterjet cutting works — allow generous grinding stock and avoid sharp internal corners.
Can Alumina 99.5 be welded?
Not weldable; join by active-metal brazing (Ti/Ag-Cu), Mo-Mn metallization plus Ni plating and brazing, glass sealing or structural adhesive.
What surface finishes work on Alumina 99.5?
Lapping/polishing gives <0.05 µm Ra optical-grade faces; metallize (Mo-Mn or thin-film Ti/Pt/Au) for solderable/brazable surfaces; no plating or painting is needed for corrosion protection.
Can Alumina 99.5 be formed, bent or molded?
Formed as a green body by dry/isostatic pressing, extrusion, slip or injection casting, then sintered at ~1600–1700 °C with ~15–20 % linear shrinkage; HIP adds a second densification cycle.
What is the maximum service temperature of Alumina 99.5?
Alumina 99.5 is rated for continuous use to about 1,700°C (3,092 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Alumina 99.5 cost?
Alumina 99.5 is a high-cost ceramic ($$$$), pricier than about 98% 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
- AD-995 Alumina 99.5 % technical data — CoorsTek (2023)
- Fine Ceramics — Alumina (A-995) material property table — Kyocera (2022)
- Engineered Materials Handbook Vol.4: Ceramics and Glasses — ASM International (1991)
- ASTM C1161 / C1327 — flexural strength and Vickers hardness of advanced ceramics — ASTM (2019)
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.