Aluminum A356/SiC/20p-T7
Temper
also Duralcan F3S.20S
T7 = solution heat treated and overaged (stabilized)
Pick for dimensional stability and better toughness at elevated service temperature, accepting ~15% lower strength.
Values for the T7 condition
Other A356/SiC/20p tempers and conditions
A356/SiC/20p is listed in 5 conditions; see the grade overview at A356/SiC/20p.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Lowest cost condition for low-stress wear parts where stiffness and CTE matter more than strength. | 135 | 190 | 0.6 | 80 HB | 26 % IACS |
Cooled from hot working and artificially aged | Choose when distortion from solution quenching is unacceptable and moderate strength is enough. | 215 | 255 | 0.5 | 95 HB | 28 % IACS |
T7This page Solution heat treated and overaged (stabilized) | Pick for dimensional stability and better toughness at elevated service temperature, accepting ~15% lower strength. | 255 | 290 | 0.9 | 100 HB | 30 % IACS |
T6Default Solution heat treated and artificially aged | Default stocked condition: maximum strength and hardness for brake rotors, pistons and wear components. | 303 | 338 | 0.5 | 118 HB | 180 W/m·K |
T6 variant, underaged | Slightly higher strength/hardness than T6 with even lower ductility; used for high-load wear surfaces. | 325 | 355 | 0.3 | 125 HB | 27 % IACS |
What is A356/SiC/20p-T7?
A356/SiC/20p-T7 is A356/SiC/20p in the T7 temper — pick for dimensional stability and better toughness at elevated service temperature, accepting ~15% lower strength. A356/SiC/20p-T7 has a yield strength of 255 MPa (37 ksi) and a tensile strength of 290 MPa (42.1 ksi) — stronger than 67% of aluminum grades. Elongation at break is 0.9% and the elastic modulus is 98 GPa (14.2 Msi). A356/SiC/20p-T7 has a density of 2.76 g/cm³ (0.0997 lb/in³), heavier than 70% of aluminum grades. It melts at 557°C (1,035 °F). T6 is the default condition FabDigit quotes; T7 is available on request or by drawing note.
Advantages
- Stiff — 98 GPa (14.2 Msi), better than 99% of aluminum grades
- High service temperature — 250°C (482 °F), better than 97% of aluminum grades
- Conducts heat well — 190 W/m·K (109.8 BTU/hr·ft·°F), better than 89% of aluminum grades
Limitations
- Difficult to machine — 17/100, worse than 99% of aluminum grades
- Limited ductility — 0.9%, worse than 97% of aluminum grades
- High embodied carbon — 14.5 kg CO₂/kg, worse than 97% of aluminum grades
- Limited formability — 9/100, worse than 86% of aluminum grades
- Difficult to weld — 25/100, worse than 76% of aluminum grades
A356/SiC/20p-T7 properties
Typical room-temperature values for A356/SiC/20p-T7; 22 are specific to this condition. Other listed values are A356/SiC/20p reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
A356/SiC/20p-T7 has a density of 2.76 g/cm³ (0.0997 lb/in³), heavier than 70% of aluminum grades. It melts at 557°C (1,035 °F).
Mechanical14
A356/SiC/20p-T7 has a yield strength of 255 MPa (37 ksi) and a tensile strength of 290 MPa (42.1 ksi) — stronger than 67% of aluminum grades. Elongation at break is 0.9% and the elastic modulus is 98 GPa (14.2 Msi).
Thermal6
A356/SiC/20p-T7 is rated for continuous service to 250°C (482 °F). It conducts heat at 190 W/m·K (109.8 BTU/hr·ft·°F), better than 89% of aluminum grades. Thermal expansion is 17.5 µm/m·K (9.72 µin/in·°F).
Electrical3
A356/SiC/20p-T7 conducts electricity at 30 % IACS, worse than 73% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 51% of aluminum grades.
Sustainability4
Producing a kilogram of A356/SiC/20p-T7 takes about 235 MJ of energy and emits 14.5 kg of CO₂ — more than 97% of aluminum grades. Typical recycled content is 10%.
Manufacturability8
A356/SiC/20p-T7's machinability is poor (17/100, worse than 99% of aluminum grades); weldability poor (25/100); formability not recommended (9/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A356/SiC/20p-T7
Is A356/SiC/20p easy to machine?
Requires polycrystalline diamond (PCD) tooling, high speed with light feeds and flood coolant; carbide wears out within minutes and grinding is best done with diamond wheels.
Can A356/SiC/20p be welded?
Fusion welding is discouraged — molten Al reacts with SiC to form brittle Al₄C₃; use mechanical fastening, adhesive bonding or friction/solid-state joining with matched MMC filler.
Can A356/SiC/20p be formed, bent or molded?
Supplied and used as a casting (sand, permanent mould, low-pressure or squeeze cast); melt must be stirred and cast below ~750 °C with short hold times to avoid particle settling and interfacial reaction; no cold forming.
What surface finishes work on A356/SiC/20p?
Anodizing gives a patchy weak film; prefer as-machined, shot-peened, painted or electroless-nickel finishes, and use diamond lapping for sealing/wear surfaces.
A356/SiC/20p 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 |
|---|---|---|
| SiCparticulate reinforcement, ≈20 vol% (typical 10–20 µm particle size); wt% basis | 21 – 25 | 23 |
| SiA356 matrix Si 6.5–7.5% of the matrix fraction | 5 – 5.8 | 5.4 |
| Mgmatrix 0.25–0.45% | 0.19 – 0.35 | 0.27 |
| Feimpurity | ≤ 0.16 | 0.09 |
| Tigrain refiner | ≤ 0.16 | 0.1 |
| Cuimpurity | ≤ 0.16 | 0.03 |
| Mnimpurity | ≤ 0.08 | 0.02 |
| Znimpurity | ≤ 0.08 | 0.02 |
| Al | balance | — |
A356/SiC/20p-T7 — frequently asked
What is A356/SiC/20p-T7 used for?
A356/SiC/20p-T7 is typically used for brake drums, clutch housings, wear plates and pump housings. In short: high wear, low ductility; diamond tooling mandatory; not fusion weldable.
What is the yield strength of A356/SiC/20p-T7?
A356/SiC/20p-T7 has a typical yield strength of 255 MPa (37 ksi) and a tensile strength of 290 MPa (42.1 ksi) — stronger than 67% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is A356/SiC/20p-T7 easy to machine?
Not especially — machinability is rated poor (17/100, worse than 99% of aluminum grades). Requires polycrystalline diamond (PCD) tooling, high speed with light feeds and flood coolant; carbide wears out within minutes and grinding is best done with diamond wheels.
Can A356/SiC/20p-T7 be welded?
Not readily — weldability is rated poor (25/100). Fusion welding is discouraged — molten Al reacts with SiC to form brittle Al₄C₃; use mechanical fastening, adhesive bonding or friction/solid-state joining with matched MMC filler.
What surface finishes work on A356/SiC/20p-T7?
Anodizing gives a patchy weak film; prefer as-machined, shot-peened, painted or electroless-nickel finishes, and use diamond lapping for sealing/wear surfaces.
Can A356/SiC/20p-T7 be formed, bent or molded?
Supplied and used as a casting (sand, permanent mould, low-pressure or squeeze cast); melt must be stirred and cast below ~750 °C with short hold times to avoid particle settling and interfacial reaction; no cold forming.
What is the maximum service temperature of A356/SiC/20p-T7?
A356/SiC/20p-T7 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A356/SiC/20p-T6 and A356/SiC/20p-F?
T6 is the default condition — default stocked condition: maximum strength and hardness for brake rotors, pistons and wear components. F: lowest cost condition for low-stress wear parts where stiffness and CTE matter more than strength. Yield strength is 303 MPa in T6 versus 135 MPa in F.
Sources
- Duralcan F3S.20S Aluminum Composite Data Sheet — Duralcan / Alcan (1996)
- ASM Handbook Vol.21: Composites — Discontinuously Reinforced Aluminum — ASM International (2001)
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys (A356 matrix) — ASM International (1990)
- ASTM B917/B917M — Heat Treatment of Aluminum-Alloy Castings — ASTM International (2018)
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.