Aluminum 6061-T6 vs. Copper C10100

Compare Aluminum 6061-T6 vs. Copper C10100 strength, stiffness, weight and thermal properties.

Mechanical	Aluminum 6061-T6	Copper C10100
Yield strength	276MPa14x stronger	69MPa2
Ultimate tensile strength	310MPa140% stronger	221MPa2
Elongation at break	17%1	45%22.65x more ductile
Young's modulus (stiffness)	68.3GPa1	117GPa21.72x stiffer
Density	2,700kg/m³13.31x lighter	8,941kg/m³2
Strength to weight	102kN·m/kg13.2x higher	7.72kN·m/kg
Stiffness to weight	25.3MN·m/kg1.93x higher	13.1MN·m/kg
Poisson's ratio	0.333	0.344
Shear modulus	25.7GPa	43.7GPa1.7x stiffer in shear
Bulk modulus	67GPa	122GPa1.82x higher
Speed of sound	5,030m/s39% faster	3,621m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Aluminum 6061-T6	Copper C10100
Thermal conductivity	167W/m·K1	391W/m·K22.34x more heat through a fin
Thermal expansion	23.6µm/m·K1	16.9µm/m·K240% less
100 mm part over a 50 °C swing	118µm growth	84.5µm growth40% less
Specific heat	896J/kg·K12.33x higher	385J/kg·K2
Heats up and cools (diffusivity)	69mm²/s	114mm²/s1.65x faster
Thermal shock resistance	19,159W/m2.13x more resistant	8,992W/m
Melting point	solidus-liquidus582–652°C1	melting point1,083°C2

Thermal conductivity against densityHigher and further left: spreads more heat for its weight

Thermal expansion against thermal conductivityLower and further right: warps less when heated

Try it on a partA bracket to run stress or thermal on, free in your browser	Open in LessCAD	Open in LessCAD

Sources4 documents: Kaiser Aluminum, Copper Development Association, U.S. Department of Defense, Wieland

Aluminum 6061-T6: 6061-T6/T651, Kaiser Aluminum typical properties; Poisson from MIL-HDBK-5J
Copper C10100: C10100 oxygen-free electronic (OFE) copper, annealed to 0.050 mm grain size (OS050), 0.04 in. flat products, copper.org typical values

1
Alloy 6061 Sheet, Coil & Plate Technical DataKaiser Aluminumarchived copyAluminum 6061-T6 · Yield strength: typical, 0.2% offset, .500 in dia specimenAluminum 6061-T6 · Ultimate tensile strength: typicalAluminum 6061-T6 · Elongation at break: typical, in 4D, 0.500 in dia specimenAluminum 6061-T6 · Young's modulus (stiffness): typicalAluminum 6061-T6 · Density: nominalAluminum 6061-T6 · Thermal conductivity: typical, 20 °CAluminum 6061-T6 · Thermal expansion: typical, mean 20-100 °CAluminum 6061-T6 · Specific heat: typical, at 100 °CAluminum 6061-T6 · Melting point: solidus-liquidus
2
C10100 Alloy (copper.org)Copper Development Associationarchived copyCopper C10100 · Yield strength: typical, 0.5% extension under load, 0.04 in. flatCopper C10100 · Ultimate tensile strength: typical, 0.04 in. flatCopper C10100 · Elongation at break: typical, 0.04 in. flatCopper C10100 · Young's modulus (stiffness): typicalCopper C10100 · Density: nominalCopper C10100 · Thermal conductivity: typical, 20 °CCopper C10100 · Thermal expansion: typical, mean 20-100 °CCopper C10100 · Specific heat: typical, 20 °CCopper C10100 · Melting point: melting point (liquidus = solidus, pure copper)
3
MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures (2003)U.S. Department of DefenseAluminum 6061-T6 · Poisson's ratio: typical (handbook physical constant)
4
Wieland-K09 (Cu-OFE, C10100) Data SheetWielandCopper C10100 · Poisson's ratio: reference value at room temperature (Wieland-K09 = Cu-OFE = C10100, rolled products)

Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Questions

Mechanical

Is Aluminum 6061-T6 stronger than Copper C10100?

Aluminum 6061-T6 is stronger: its yield strength is 276 MPa against 69 MPa for Copper C10100 (4x).

Which is lighter, Aluminum 6061-T6 or Copper C10100?

Aluminum 6061-T6 is lighter: 2,700 kg/m³ against 8,941 kg/m³ for Copper C10100.

Which is stiffer, Aluminum 6061-T6 or Copper C10100?

Copper C10100 is stiffer: Young's modulus 117 GPa against 68.3 GPa for Aluminum 6061-T6, so the same part in Copper C10100 deflects less under the same load.

Which is lighter for the same job, Aluminum 6061-T6 or Copper C10100?

For the same stiffness or strength: Aluminum 6061-T6 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum 6061-T6	Copper C10100
Stiff rod or tie (tension)	lighter	1.93x heavier
Stiff beam (bending)	lighter	2.53x heavier
Stiff panel or plate	lighter	2.77x heavier
Strong rod or tie	lighter	13.2x heavier
Strong beam	lighter	8.34x heavier
Strong panel or plate	lighter	6.62x heavier

For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).

Which is more ductile, Aluminum 6061-T6 or Copper C10100?

Copper C10100 stretches further before it breaks: 45% elongation at break against 17% for Aluminum 6061-T6.

Thermal

Which conducts heat better, Aluminum 6061-T6 or Copper C10100?

Copper C10100 conducts heat better: 391 W/m·K against 167 W/m·K for Aluminum 6061-T6.

Which expands less with temperature?

Copper C10100 expands less: 16.9 µm/m·K against 23.6 µm/m·K for Aluminum 6061-T6.