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Aluminum A356/SiC/20p-T6

Temper · default condition

also Duralcan F3S.20S

T6 = solution heat treated and artificially aged

Default stocked condition: maximum strength and hardness for brake rotors, pistons and wear components.

High cost $$$$

Values for the T6 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 datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
As fabricated
Lowest cost condition for low-stress wear parts where stiffness and CTE matter more than strength.1351900.680 HB26 % IACS
Cooled from hot working and artificially aged
Choose when distortion from solution quenching is unacceptable and moderate strength is enough.2152550.595 HB28 % IACS
Solution heat treated and overaged (stabilized)
Pick for dimensional stability and better toughness at elevated service temperature, accepting ~15% lower strength.2552900.9100 HB30 % IACS
T6DefaultThis page
Solution heat treated and artificially aged
Default stocked condition: maximum strength and hardness for brake rotors, pistons and wear components.3033380.5118 HB180 W/m·K
T6 variant, underaged
Slightly higher strength/hardness than T6 with even lower ductility; used for high-load wear surfaces.3253550.3125 HB27 % IACS

What is A356/SiC/20p-T6?

A356/SiC/20p-T6 is A356/SiC/20p in the T6 temper — default stocked condition: maximum strength and hardness for brake rotors, pistons and wear components. A356/SiC/20p-T6 has a yield strength of 303 MPa (43.9 ksi) and a tensile strength of 338 MPa (49 ksi) — stronger than 77% of aluminum grades. Elongation at break is 0.5% and the elastic modulus is 98 GPa (14.2 Msi). A356/SiC/20p-T6 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).

Advantages

  • Stiff — 98 GPa (14.2 Msi), better than 99% of aluminum grades
  • High service temperature — 200°C (392 °F), better than 90% of aluminum grades
  • Conducts heat well — 180 W/m·K (104 BTU/hr·ft·°F), better than 86% of aluminum grades
  • High strength — 303 MPa (43.9 ksi), better than 77% of aluminum grades

Limitations

  • Difficult to machine — 15/100, worse than 100% of aluminum grades
  • Limited ductility — 0.5%, worse than 99% of aluminum grades
  • Low fracture toughness — 14 MPa·√m (12.7 ksi·√in), worse than 97% of aluminum grades
  • High embodied carbon — 14.5 kg CO₂/kg, worse than 97% of aluminum grades
  • Limited formability — 8/100, worse than 88% of aluminum grades

A356/SiC/20p-T6 properties

Typical room-temperature values for A356/SiC/20p-T6; 10 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-T6 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).

Density2.76 g/cm³0.1 lb/in³
Melting Point (Solidus)557°C1,035 °F
Liquidus Temperature613°C1,135 °F

Mechanical14

A356/SiC/20p-T6 has a yield strength of 303 MPa (43.9 ksi) and a tensile strength of 338 MPa (49 ksi) — stronger than 77% of aluminum grades. Elongation at break is 0.5% and the elastic modulus is 98 GPa (14.2 Msi).

Elastic (Young's) Modulus98 GPa14.2 Msi
Shear Modulus38 GPa5.5 Msi
Bulk Modulus81 GPa11.7 Msi
Poisson's Ratio0.3
Tensile Strength (Ultimate)338 MPa49 ksi
Yield Strength (0.2% offset)303 MPa43.9 ksi
Elongation at Break0.5%
Compressive Strength500 MPa72.5 ksi
Shear Strength205 MPa29.7 ksi
Fatigue Strength (Endurance Limit)120 MPa17.4 ksi
Fracture Toughness (K_IC)14 MPa·√m12.7 ksi·√in
Charpy V-Notch Impact (RT)2 J1.5 ft·lbf
Hardness, Brinell118 HB
Hardness, Vickers125 HV

Thermal6

A356/SiC/20p-T6 is rated for continuous service to 200°C (392 °F). It conducts heat at 180 W/m·K (104 BTU/hr·ft·°F), better than 86% of aluminum grades. Thermal expansion is 17.5 µm/m·K (9.72 µin/in·°F).

Thermal Conductivity180 W/m·K104 BTU/hr·ft·°F
Specific Heat Capacity854 J/kg·K0.2 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)17.5 µm/m·K9.7 µin/in·°F
Latent Heat of Fusion300 J/g129 BTU/lb
Max Service Temperature (continuous)200°C392 °F
Min Service Temperature-196°C-321 °F

Electrical3

A356/SiC/20p-T6 conducts electricity at 28 % IACS, worse than 82% of aluminum grades.

Electrical Conductivity28 % IACS
Electrical Resistivity6.2×10⁻⁸ Ω·m2.44 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is fair (52/100), worse than 55% of aluminum grades.

Galvanic Potential (seawater, vs SCE)-0.82 V
Corrosion ResistanceFair52/100
Chemical Resistance SummaryGood in dry air, neutral coolants and most hydrocarbons; the SiC/matrix interfaces act as pit-initiation sites in chlorides and the material is attacked by strong acids and alkalis — protective coatings recommended for marine or de-icing-salt service.

Sustainability4

Producing a kilogram of A356/SiC/20p-T6 takes about 235 MJ of energy and emits 14.5 kg of CO₂ — more than 97% of aluminum grades. Typical recycled content is 10%.

Embodied Energy (primary production)235 MJ/kg101,032 BTU/lb
Embodied Carbon (primary production)14.5 kg CO₂/kg
Embodied Water1,150 L/kg138 gal/lb
Typical Recycled Content10%

Manufacturability8

A356/SiC/20p-T6's machinability is poor (15/100, worse than 100% of aluminum grades); weldability poor (25/100); formability not recommended (8/100).

MachinabilityPoor15/100
Machinability Rating (AISI 1212 = 100 %)12%
WeldabilityPoor25/100
Formability (cold)Not recommended8/100
CastabilityVery good70/100
Brazeability / SolderabilityPoor30/100
PolishabilityFair45/100
Anodizing Responsepoor — SiC particles do not convert, giving a porous, patchy and mechanically weak anodic film; hard anodizing is generally not specified for this composite.

Common Calculations5

Specific Strength (UTS / density)calculated122 kN·m/kg
Specific Stiffness (E / density)calculated35.5 MN·m/kg
Modulus of Resiliencecalculated468 kJ/m³
Thermal Diffusivitycalculated76.4 mm²/s
Thermal Shock Resistance Indexcalculated35

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with A356/SiC/20p-T6

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.

ElementSpec limit (wt %)Nominal
SiCparticulate reinforcement, ≈20 vol% (typical 10–20 µm particle size); wt% basis21 – 2523
SiA356 matrix Si 6.5–7.5% of the matrix fraction5 – 5.85.4
Mgmatrix 0.25–0.45%0.19 – 0.350.27
Feimpurity≤ 0.160.09
Tigrain refiner≤ 0.160.1
Cuimpurity≤ 0.160.03
Mnimpurity≤ 0.080.02
Znimpurity≤ 0.080.02
Albalance—

A356/SiC/20p-T6 — frequently asked

What is A356/SiC/20p-T6 used for?

A356/SiC/20p-T6 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-T6?

A356/SiC/20p-T6 has a typical yield strength of 303 MPa (43.9 ksi) and a tensile strength of 338 MPa (49 ksi) — stronger than 77% of aluminum grades. Strength varies by condition: see the 5 listed tempers.

Is A356/SiC/20p-T6 easy to machine?

Not especially — machinability is rated poor (15/100, worse than 100% 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-T6 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-T6?

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-T6 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-T6?

A356/SiC/20p-T6 is rated for continuous use to about 200°C (392 °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

  1. Duralcan F3S.20S Aluminum Composite Data Sheet — Duralcan / Alcan (1996)
  2. ASM Handbook Vol.21: Composites — Discontinuously Reinforced Aluminum — ASM International (2001)
  3. ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys (A356 matrix) — ASM International (1990)
  4. 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.