A359/SiC/20p T71
Precip hard
also Duralcan F3S.20S
T71 = solution treated and overaged
Pick for elevated-temperature dimensional stability and highest thermal conductivity, accepting lower strength.
Values for the T71 condition
Other A359/SiC/20p grades and fills
A359/SiC/20p is listed in 5 conditions; see the grade overview at A359/SiC/20p.
Compare all 5 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
As fabricated | Lowest-cost condition for non-critical wear or thermal parts where peak strength is not needed. | 155 | 230 | 0.8 | — |
Cooled from hot working and artificially aged | Choose when distortion from solution treatment must be avoided but some strengthening is wanted. | 235 | 275 | 0.6 | — |
T71This page Solution treated and overaged | Pick for elevated-temperature dimensional stability and highest thermal conductivity, accepting lower strength. | 255 | 290 | 0.8 | — |
T6 variant, underaged | Slightly below peak strength with marginally better ductility and dimensional stability than T6. | 303 | 338 | 0.4 | — |
T6Default Solution heat treated and artificially aged | Default structural condition: maximum strength and stiffness for brake rotors, pistons and load-bearing castings. | 310 | 340 | 0.5 | — |
What is A359/SiC/20p T71?
A359/SiC/20p T71 is A359/SiC/20p in the T71 condition — pick for elevated-temperature dimensional stability and highest thermal conductivity, accepting lower strength. A359/SiC/20p T71 has a yield strength of 255 MPa (37 ksi) and a tensile strength of 290 MPa (42.1 ksi) — weaker than 58% of composite grades. Elongation at break is 0.8% and the elastic modulus is 98.6 GPa (14.3 Msi). A359/SiC/20p T71 has a density of 2.77 g/cm³ (0.1 lb/in³), heavier than 88% of composite grades. T6 is the default condition FabDigit quotes; T71 is available on request or by drawing note.
Advantages
- Conducts heat well — 192 W/m·K (110.9 BTU/hr·ft·°F), better than 97% of composite grades
- Good UV / weathering resistance — 95/100, better than 78% of composite grades
Limitations
- Needs corrosion protection — 50/100, worse than 92% of composite grades
- Heavy — 2.77 g/cm³ (0.1 lb/in³), worse than 88% of composite grades
- Difficult to machine — 14/100, worse than 86% of composite grades
- Limited ductility — 0.8%, worse than 82% of composite grades
A359/SiC/20p T71 properties
Typical room-temperature values for A359/SiC/20p T71; 14 are specific to this condition. Other listed values are A359/SiC/20p reference data and may not represent this condition. Bars are the position among composite grades.
Physical1
A359/SiC/20p T71 has a density of 2.77 g/cm³ (0.1 lb/in³), heavier than 88% of composite grades.
Mechanical13
A359/SiC/20p T71 has a yield strength of 255 MPa (37 ksi) and a tensile strength of 290 MPa (42.1 ksi) — weaker than 58% of composite grades. Elongation at break is 0.8% and the elastic modulus is 98.6 GPa (14.3 Msi).
Thermal6
A359/SiC/20p T71 is rated for continuous service to 230°C (446 °F). It conducts heat at 192 W/m·K (110.9 BTU/hr·ft·°F), better than 97% of composite grades. Thermal expansion is 17.5 µm/m·K (9.72 µin/in·°F).
Electrical1
A359/SiC/20p T71 has an electrical resistivity of 5.5×10⁻⁸ Ω·m.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 92% of composite grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of A359/SiC/20p T71 takes about 190 MJ of energy and emits 13 kg of CO₂ — less than 53% of composite grades. Typical recycled content is 15%.
Manufacturability2
A359/SiC/20p T71's machinability is not recommended (14/100, worse than 86% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A359/SiC/20p T71
Is A359/SiC/20p easy to machine?
Abrasive to conventional carbide — use PCD or diamond-coated tools, high speed / light feed, flood coolant; grinding and EDM are practical for finishing.
Can A359/SiC/20p be welded?
Fusion welding is problematic (SiC reacts with molten Al forming Al4C3); prefer mechanical fastening, adhesive bonding or specialized friction-stir / brazing procedures.
Can A359/SiC/20p be formed, bent or molded?
Supplied as sand, permanent-mold, squeeze or die castings; keep melt stirred and pouring temperature low to avoid particle settling and interfacial reaction — cold forming is not feasible.
What surface finishes work on A359/SiC/20p?
Shot blast or machine to size; anodizing is uneven because of exposed SiC, so chromate/phosphate conversion, e-coat or paint are the usual protection routes; lapping gives excellent flatness for thermal baseplates.
A359/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 |
|---|---|---|
| SiC (particulate reinforcement)20 vol% ≈ 23 wt%; typical mean particle size 10–20 µm | 21 – 25 | 23 |
| Simatrix A359 basis | 8.5 – 9.5 | 9 |
| Mgmatrix A359 basis | 0.45 – 0.7 | 0.55 |
| Fe | ≤ 0.2 | 0.12 |
| Cu | ≤ 0.2 | 0.05 |
| Mn | ≤ 0.1 | 0.03 |
| Zn | ≤ 0.1 | 0.03 |
| Ti | ≤ 0.2 | 0.1 |
| Al | balance | — |
A359/SiC/20p T71 — frequently asked
What is A359/SiC/20p T71 used for?
A359/SiC/20p T71 is typically used for brake rotors/calipers, electronic housings, aerospace brackets and optical mounts. In short: wear-resistant cast MMC; 180 W/m·K with low CTE; stiffer than cast aluminium.
What is the yield strength of A359/SiC/20p T71?
A359/SiC/20p T71 has a typical yield strength of 255 MPa (37 ksi) and a tensile strength of 290 MPa (42.1 ksi) — weaker than 58% of composite grades. Strength varies by condition: see the 5 listed tempers.
Is A359/SiC/20p T71 easy to machine?
Not especially — machinability is rated not recommended (14/100, worse than 86% of composite grades). Abrasive to conventional carbide — use PCD or diamond-coated tools, high speed / light feed, flood coolant; grinding and EDM are practical for finishing.
Can A359/SiC/20p T71 be welded?
Fusion welding is problematic (SiC reacts with molten Al forming Al4C3); prefer mechanical fastening, adhesive bonding or specialized friction-stir / brazing procedures.
What surface finishes work on A359/SiC/20p T71?
Shot blast or machine to size; anodizing is uneven because of exposed SiC, so chromate/phosphate conversion, e-coat or paint are the usual protection routes; lapping gives excellent flatness for thermal baseplates.
Can A359/SiC/20p T71 be formed, bent or molded?
Supplied as sand, permanent-mold, squeeze or die castings; keep melt stirred and pouring temperature low to avoid particle settling and interfacial reaction — cold forming is not feasible.
What is the maximum service temperature of A359/SiC/20p T71?
A359/SiC/20p T71 is rated for continuous use to about 230°C (446 °F), and briefly to 300°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A359/SiC/20p T6 and A359/SiC/20p F?
T6 is the default condition — default structural condition: maximum strength and stiffness for brake rotors, pistons and load-bearing castings. F: lowest-cost condition for non-critical wear or thermal parts where peak strength is not needed. Yield strength is 310 MPa in T6 versus 155 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)
- ASTM B917 / ANSI H35.5 aluminum MMC designation practice — ASTM (2020)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys (A359 matrix data) — ASM International (1993)
- SiCp/Al (2025)
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.