Aluminum AC9B-T5
Temper
JIS AC9B
T5 = cooled from hot working and artificially aged
Choose when moderate strengthening and dimensional stabilization are needed without the distortion risk of solution treatment.
Values for the T5 condition
Other AC9B tempers and conditions
AC9B is listed in 4 conditions; see the grade overview at AC9B.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Lowest-cost condition for non-critical wear castings where dimensional stabilization is not required. | 150 | 170 | 0.5 | 100 HB | 26 % IACS |
Solution heat treated and overaged (stabilized) | Choose for maximum dimensional/thermal stability in long-running hot components, accepting some strength loss versus T6. | 165 | 185 | 0.8 | 110 HB | 27 % IACS |
T5This page Cooled from hot working and artificially aged | Choose when moderate strengthening and dimensional stabilization are needed without the distortion risk of solution treatment. | 175 | 190 | 0.5 | 115 HB | 26 % IACS |
T6Default Solution heat treated and artificially aged | Standard condition for maximum strength and hardness in pistons and wear parts operating up to about 250 °C. | 200 | 220 | 0.5 | 140 HB | 25 % IACS |
What is AC9B-T5?
AC9B-T5 is AC9B in the T5 temper — choose when moderate strengthening and dimensional stabilization are needed without the distortion risk of solution treatment. AC9B-T5 has a yield strength of 175 MPa (25.4 ksi) and a tensile strength of 190 MPa (27.6 ksi) — weaker than 55% of aluminum grades. Elongation at break is 0.5% and the elastic modulus is 82 GPa (11.9 Msi). AC9B-T5 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 507°C (945 °F). T6 is the default condition FabDigit quotes; T5 is available on request or by drawing note.
Advantages
- Stiff — 82 GPa (11.9 Msi), better than 97% of aluminum grades
- High service temperature — 230°C (446 °F), better than 95% of aluminum grades
- Low embodied carbon — 10.5 kg CO₂/kg, better than 95% of aluminum grades
Limitations
- Limited formability — 3/100, worse than 100% of aluminum grades
- Limited ductility — 0.5%, worse than 99% of aluminum grades
- Difficult to machine — 29/100, worse than 94% of aluminum grades
- Low fracture toughness — 15 MPa·√m (13.7 ksi·√in), worse than 93% of aluminum grades
- Low electrical conductivity — 26 % IACS, worse than 90% of aluminum grades
AC9B-T5 properties
Typical room-temperature values for AC9B-T5; 22 are specific to this condition. Other listed values are AC9B reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
AC9B-T5 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 507°C (945 °F).
Mechanical13
AC9B-T5 has a yield strength of 175 MPa (25.4 ksi) and a tensile strength of 190 MPa (27.6 ksi) — weaker than 55% of aluminum grades. Elongation at break is 0.5% and the elastic modulus is 82 GPa (11.9 Msi).
Thermal6
AC9B-T5 is rated for continuous service to 230°C (446 °F). It conducts heat at 135 W/m·K (78 BTU/hr·ft·°F), worse than 58% of aluminum grades. Thermal expansion is 17.8 µm/m·K (9.89 µin/in·°F).
Electrical3
AC9B-T5 conducts electricity at 26 % IACS, worse than 90% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), worse than 58% of aluminum grades.
Sustainability4
Producing a kilogram of AC9B-T5 takes about 155 MJ of energy and emits 10.5 kg of CO₂ — less than 94% of aluminum grades. Typical recycled content is 55%.
Manufacturability8
AC9B-T5's machinability is poor (29/100, worse than 94% of aluminum grades); weldability poor (22/100); formability not recommended (3/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with AC9B-T5
Is AC9B easy to machine?
Highly abrasive primary silicon — use PCD or diamond-coated tooling, high speed / light feed with flood coolant; carbide life is very short.
Can AC9B be welded?
Poor fusion weldability (hot cracking, porosity, Cu pickup); repair only with 4047/4145-type filler and preheat, avoid on load-bearing sections.
Can AC9B be formed, bent or molded?
Permanent-mold/gravity or squeeze cast at 730–780 °C with phosphorus modification and controlled cooling to keep primary Si fine and evenly distributed.
What surface finishes work on AC9B?
Hard anodizing or ferrous/tin coatings on ring grooves and skirts for wear; decorative anodizing looks dark and mottled, so painting or shot-blast finishes are usual.
AC9B 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 |
|---|---|---|
| Sihypereutectic; refined with P (AlP nuclei) | 18 – 20 | 19 |
| Cu | 0.5 – 1.5 | 1 |
| Mg | 0.5 – 1.5 | 1 |
| Nihigh-temperature strength | 0.5 – 1.5 | 1 |
| Feimpurity limit | ≤ 0.8 | 0.5 |
| Mnimpurity limit | ≤ 0.5 | — |
| Znimpurity limit | ≤ 0.2 | — |
| Tiimpurity limit | ≤ 0.2 | — |
| Crimpurity limit | ≤ 0.1 | — |
| Pbimpurity limit | ≤ 0.05 | — |
| Snimpurity limit | ≤ 0.05 | — |
| Al | balance | — |
AC9B-T5 — frequently asked
What is AC9B-T5 used for?
AC9B-T5 is typically used for high-performance pistons, cylinder liners, wear-resistant sleeves, compressor pistons, pump and valve wear plates and high-temperature engine wear parts. In short: hardest AC casting alloy; hypereutectic liner grade; diamond tooling required.
What is the yield strength of AC9B-T5?
AC9B-T5 has a typical yield strength of 175 MPa (25.4 ksi) and a tensile strength of 190 MPa (27.6 ksi) — weaker than 55% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is AC9B-T5 easy to machine?
Not especially — machinability is rated poor (29/100, worse than 94% of aluminum grades). Highly abrasive primary silicon — use PCD or diamond-coated tooling, high speed / light feed with flood coolant; carbide life is very short.
Can AC9B-T5 be welded?
Not readily — weldability is rated poor (22/100). Poor fusion weldability (hot cracking, porosity, Cu pickup); repair only with 4047/4145-type filler and preheat, avoid on load-bearing sections.
What surface finishes work on AC9B-T5?
Hard anodizing or ferrous/tin coatings on ring grooves and skirts for wear; decorative anodizing looks dark and mottled, so painting or shot-blast finishes are usual.
Can AC9B-T5 be formed, bent or molded?
Permanent-mold/gravity or squeeze cast at 730–780 °C with phosphorus modification and controlled cooling to keep primary Si fine and evenly distributed.
What is the maximum service temperature of AC9B-T5?
AC9B-T5 is rated for continuous use to about 230°C (446 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AC9B-T6 and AC9B-F?
T6 is the default condition — standard condition for maximum strength and hardness in pistons and wear parts operating up to about 250 °C. F: lowest-cost condition for non-critical wear castings where dimensional stabilization is not required. Yield strength is 200 MPa in T6 versus 150 MPa in F.
Sources
- JIS H5202 Aluminium alloy castings — JSA (2010)
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys (A390 hypereutectic Al-Si data) — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- ASTM B108 / Aluminum Association Pink Sheets (A390.0) — ASTM / The Aluminum Association (2019)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.