Aluminum Al2O3f/AC8A
Al2O3f/AC8A is the AC8A piston alloy locally reinforced with short alumina-silica fibers, squeeze-cast into the ring-groove region and available as F, T5, T6, T7 and Vf5, Vf12, Vf20 T6 variants.
Reference datasheet — Al2O3f/AC8A 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 T6 condition
Al2O3f/AC8A tempers and conditions
Al2O3f/AC8A is supplied in 7 conditions, soft to hard. T6 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Pick for prototype pistons or where subsequent T5/T6 ageing is done downstream; lowest strength, highest residual stress. | 150 | 195 | 0.9 | 95 HB | 27 % IACS |
Cooled from hot working and artificially aged | Low-distortion option for thin-wall pistons: modest strength gain without a solution quench. | 185 | 220 | 0.7 | 108 HB | 26 % IACS |
Solution heat treated and overaged (stabilized) | Choose when long-term dimensional stability and growth resistance at 300–350 °C matter more than peak strength. | 200 | 230 | 1 | 108 HB | 29 % IACS |
5 vol% Al2O3-SiO2 short fibre, T6 | Low fibre loading for easier infiltration and better thermal conduction where only moderate groove wear resistance is needed. | 215 | 255 | 1 | 115 HB | 27 % IACS |
T6Default Solution heat treated and artificially aged | Standard production condition for fibre-reinforced diesel pistons — highest room- and elevated-temperature strength and ring-groove wear resistance. | 230 | 260 | 0.6 | 125 HB | 24 % IACS |
12 vol% Al2O3-SiO2 short fibre, T6 | The classic Toyota ring-groove reinforcement level — best balance of wear resistance, thermal fatigue life and machinability. | 230 | 260 | 0.6 | 125 HB | 24 % IACS |
20 vol% Al2O3-SiO2 short fibre, T6 | Maximum stiffness and wear/creep resistance for high-BMEP diesel pistons; lowest ductility, hardest to infiltrate and machine. | 250 | 0.3 | 145 HB | 88 W/m·K |
What is Al2O3f/AC8A?
Al2O3f/AC8A is the AC8A piston alloy locally reinforced with short alumina-silica fibers, squeeze-cast into the ring-groove region and available as F, T5, T6, T7 and Vf5, Vf12, Vf20 T6 variants. It is used where wear and heat resistance are needed only in one zone of a casting, giving 230 MPa yield, 260 MPa tensile, 125 HB and a 350 °C maximum service temperature. Elongation is 0.6 % and thermal conductivity 100 W/m·K, so the part is not weldable and cannot be wrought after casting. Cast-iron ring carriers are the conventional alternative. Al2O3f/AC8A has a density of 2.79 g/cm³ (0.101 lb/in³), heavier than 77% of aluminum grades. It melts at 520°C (968 °F). Al2O3f/AC8A has a yield strength of 230 MPa (33.4 ksi) and a tensile strength of 260 MPa (37.7 ksi) — stronger than 60% of aluminum grades. Elongation at break is 0.6% and the elastic modulus is 95 GPa (13.8 Msi).
What is Al2O3f/AC8A used for?
- diesel engine pistons
- ring-groove reinforcement inserts
- high-temperature wear zones
Advantages
- High service temperature — 350°C (662 °F), better than 100% of aluminum grades
- Stiff — 95 GPa (13.8 Msi), better than 99% of aluminum grades
- Low embodied carbon — 9 kg CO₂/kg, better than 99% of aluminum grades
Limitations
- Low fracture toughness — 12 MPa·√m (10.9 ksi·√in), worse than 99% of aluminum grades
- Difficult to machine — 20/100, worse than 99% of aluminum grades
- Difficult to weld — 10/100, worse than 99% of aluminum grades
- Limited ductility — 0.6%, worse than 98% of aluminum grades
- Low electrical conductivity — 24 % IACS, worse than 95% of aluminum grades
Al2O3f/AC8A properties
Typical room-temperature values for Al2O3f/AC8A-T6; bars are the position among aluminum grades.
Physical3
Al2O3f/AC8A has a density of 2.79 g/cm³ (0.101 lb/in³), heavier than 77% of aluminum grades. It melts at 520°C (968 °F).
Mechanical16
Al2O3f/AC8A has a yield strength of 230 MPa (33.4 ksi) and a tensile strength of 260 MPa (37.7 ksi) — stronger than 60% of aluminum grades. Elongation at break is 0.6% and the elastic modulus is 95 GPa (13.8 Msi).
Thermal6
Al2O3f/AC8A is rated for continuous service to 350°C (662 °F). It conducts heat at 100 W/m·K (57.8 BTU/hr·ft·°F), worse than 93% of aluminum grades. Thermal expansion is 17.5 µm/m·K (9.72 µin/in·°F).
Electrical3
Al2O3f/AC8A conducts electricity at 24 % IACS, worse than 95% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (42/100), worse than 69% of aluminum grades.
Sustainability4
Producing a kilogram of Al2O3f/AC8A takes about 120 MJ of energy and emits 9 kg of CO₂ — less than 99% of aluminum grades. Typical recycled content is 25%.
Manufacturability8
Al2O3f/AC8A's machinability is poor (20/100, worse than 99% of aluminum grades); weldability not recommended (10/100); formability not recommended (5/100).
Common Calculations5
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 aluminum family
Yield strength against density for every aluminum grade FabDigit runs. Al2O3f/AC8A is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Al2O3f/AC8A
Is Al2O3f/AC8A easy to machine?
Turn/bore the ring-groove zone with PCD or fine-grain diamond-coated tooling at moderate speed and light feed; carbide wears out in minutes against the alumina fibres, and grinding is preferred for finishing.
Can Al2O3f/AC8A be welded?
Not fusion weldable — arc heat collapses fibre distribution and forms brittle interface phases; use mechanical joining or friction/solid-state processes only, and repair by re-casting is not practical.
Can Al2O3f/AC8A be formed, bent or molded?
Made only by squeeze casting / pressure infiltration of a fibre preform (typically 70–100 MPa, preform preheat ~700–800 °C, die ~250–350 °C); no wrought forming afterwards.
Al2O3f/AC8A 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 |
|---|---|---|
| SiJIS H5202 AC8A matrix | 11 – 13 | 12 |
| Cu | 0.8 – 1.3 | 1 |
| Mg | 0.7 – 1.3 | 1 |
| Nihigh-temperature strength | 0.8 – 1.5 | 1.1 |
| Feimpurity limit | ≤ 0.8 | 0.4 |
| Mn | ≤ 0.15 | 0.05 |
| Zn | ≤ 0.15 | 0.05 |
| Tigrain refiner | ≤ 0.2 | 0.1 |
| Cr | ≤ 0.1 | |
| Sn | ≤ 0.1 | |
| Pb | ≤ 0.1 | |
| Al2O3-SiO2 short fibre (Saffil type, ~96vol %, local preform in ring-groove zone only | 5 – 20 | 12 |
| Almatrix balance | balance |
What surface finishes work on Al2O3f/AC8A?
Ring grooves are ground or PCD-finished; hard anodizing over the reinforced band is uneven, so tin plating, graphite skirt coating or thermal-barrier crown coatings are used instead.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Aluminum Al2O3f/AC8A in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- AC8A
How much does Al2O3f/AC8A cost?
Al2O3f/AC8A is a high-cost aluminum ($$$$), 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.
Al2O3f/AC8A — frequently asked
What is Al2O3f/AC8A used for?
Al2O3f/AC8A is typically used for diesel engine pistons, ring-groove reinforcement inserts and high-temperature wear zones. In short: locally reinforced piston alloy; 350 °C ring-groove wear zone; ring-carrier replacement.
What is the yield strength of Al2O3f/AC8A?
Al2O3f/AC8A has a typical yield strength of 230 MPa (33.4 ksi) and a tensile strength of 260 MPa (37.7 ksi) — stronger than 60% of aluminum grades. Strength varies by condition: see the 7 listed tempers.
Is Al2O3f/AC8A easy to machine?
Not especially — machinability is rated poor (20/100, worse than 99% of aluminum grades). Turn/bore the ring-groove zone with PCD or fine-grain diamond-coated tooling at moderate speed and light feed; carbide wears out in minutes against the alumina fibres, and grinding is preferred for finishing.
Can Al2O3f/AC8A be welded?
Not readily — weldability is rated not recommended (10/100). Not fusion weldable — arc heat collapses fibre distribution and forms brittle interface phases; use mechanical joining or friction/solid-state processes only, and repair by re-casting is not practical.
What surface finishes work on Al2O3f/AC8A?
Ring grooves are ground or PCD-finished; hard anodizing over the reinforced band is uneven, so tin plating, graphite skirt coating or thermal-barrier crown coatings are used instead.
Can Al2O3f/AC8A be formed, bent or molded?
Made only by squeeze casting / pressure infiltration of a fibre preform (typically 70–100 MPa, preform preheat ~700–800 °C, die ~250–350 °C); no wrought forming afterwards.
What is the maximum service temperature of Al2O3f/AC8A?
Al2O3f/AC8A is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Al2O3f/AC8A-T6 and Al2O3f/AC8A-F?
T6 is the default condition — standard production condition for fibre-reinforced diesel pistons — highest room- and elevated-temperature strength and ring-groove wear resistance. F: pick for prototype pistons or where subsequent T5/T6 ageing is done downstream; lowest strength, highest residual stress. Yield strength is 230 MPa in T6 versus 150 MPa in F.
How much does Al2O3f/AC8A cost?
Al2O3f/AC8A is a high-cost aluminum ($$$$), 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
- JIS H5202 — Aluminium alloy castings (AC8A) — JSA (2010)
- ASM Handbook Vol.21 — Composites (discontinuously reinforced aluminium) — ASM International (2001)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- SAE 830252 — Ceramic fiber reinforced piston for high performance diesel engines — SAE International (1983)
- Saffil alumina short fibre (RF/LD grades) technical data — Saffil Ltd / Unifrax (2015)
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.