Aluminum 5052-H32 vs. Magnesium AZ31B-H24

Compare Aluminum 5052-H32 vs. Magnesium AZ31B-H24 strength, stiffness, weight and thermal properties.

Mechanical	Aluminum 5052-H32	Magnesium AZ31B-H24
Yield strength	195MPa1	220MPa213% stronger
Ultimate tensile strength	230MPa1	290MPa226% stronger
Elongation at break	12%1	13%2
Young's modulus (stiffness)	70GPa11.56x stiffer	44.8GPa3
Density	2,685kg/m³3	1,769kg/m³31.52x lighter
Strength to weight	72.6kN·m/kg	124kN·m/kg1.71x higher
Stiffness to weight	26.1MN·m/kg3% higher	25.3MN·m/kg
Poisson's ratio	0.333	0.353
Shear modulus	26.3GPa1.59x stiffer in shear	16.6GPa
Bulk modulus	68.6GPa38% higher	49.8GPa
Speed of sound	5,106m/s1% faster	5,032m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Aluminum 5052-H32	Magnesium AZ31B-H24
Thermal conductivity	base material138W/m·K11.79x more heat through a fin	76.9W/m·K2
Thermal expansion	23.8µm/m·K113% less	26.8µm/m·K2
100 mm part over a 50 °C swing	119µm growth13% less	134µm growth
Specific heat	at 100 °C963J/kg·K3	1,040J/kg·K2
Heats up and cools (diffusivity)	53.4mm²/s28% faster	41.8mm²/s
Thermal shock resistance	10,822W/m18% more resistant	9,159W/m
Melting point	melting range605–650°C1	not sourced
Max service temperature	not sourced	149°C3

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

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Sources3 documents: Kaiser Aluminum, Magnesium Elektron, U.S. Department of Defense

Aluminum 5052-H32: 5052-H32, Kaiser Aluminum tube & pipe typical datasheet (mechanical, CTE, melting); MIL-HDBK-5J (Poisson, density, specific heat)
Magnesium AZ31B-H24: AZ31B-H24 sheet 0.016-0.062 in., MIL-HDBK-5J Table 4.2.1.0(b) (AMS 4377); strengths are S-basis MINIMUMS

1
Alloy 5052 Tube & Pipe Technical DataKaiser Aluminumarchived copyAluminum 5052-H32 · Yield strength: typical, 0.2% offsetAluminum 5052-H32 · Ultimate tensile strength: typicalAluminum 5052-H32 · Elongation at break: typicalAluminum 5052-H32 · Young's modulus (stiffness): typicalAluminum 5052-H32 · Thermal conductivity: base material: 5052 in O temper (same alloy, annealed); Kaiser typicalAluminum 5052-H32 · Thermal expansion: typical, mean 20-100 °CAluminum 5052-H32 · Melting point: melting range
2
Elektron AZ31B Sheet, Plate & Coil (Datasheet 482)Magnesium Elektronarchived copyMagnesium AZ31B-H24 · Yield strength: typical, H24, 0.5-6 mm, 0.2 % proof stressMagnesium AZ31B-H24 · Ultimate tensile strength: typical, H24, 0.5-6 mmMagnesium AZ31B-H24 · Elongation at break: typical, H24, 0.5-6 mm, gauge 5.65√AMagnesium AZ31B-H24 · Thermal conductivity: typical (temper/temperature not stated)Magnesium AZ31B-H24 · Thermal expansion: typical (temperature range not stated)Magnesium AZ31B-H24 · Specific heat: typical
3
MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures (2003)U.S. Department of DefenseMagnesium AZ31B-H24 · Young's modulus (stiffness): typical (handbook physical constant)Aluminum 5052-H32 · Density: nominalMagnesium AZ31B-H24 · Density: nominalAluminum 5052-H32 · Poisson's ratio: typical (handbook physical constant)Magnesium AZ31B-H24 · Poisson's ratio: typical (handbook physical constant)Aluminum 5052-H32 · Specific heat: at 100 °C (212 °F); table covers O, H32, H34, H36, H38Magnesium AZ31B-H24 · Max service temperature: stated application limit

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 5052-H32 stronger than Magnesium AZ31B-H24?

Magnesium AZ31B-H24 is stronger: its yield strength is 220 MPa against 195 MPa for Aluminum 5052-H32 (13%).

Which is lighter, Aluminum 5052-H32 or Magnesium AZ31B-H24?

Magnesium AZ31B-H24 is lighter: 1,769 kg/m³ against 2,685 kg/m³ for Aluminum 5052-H32.

Which is stiffer, Aluminum 5052-H32 or Magnesium AZ31B-H24?

Aluminum 5052-H32 is stiffer: Young's modulus 70 GPa against 44.8 GPa for Magnesium AZ31B-H24, so the same part in Aluminum 5052-H32 deflects less under the same load.

Which is lighter for the same job, Aluminum 5052-H32 or Magnesium AZ31B-H24?

For the same stiffness or strength: Aluminum 5052-H32 is lighter for a stiff rod or tie (tension); Magnesium AZ31B-H24 is lighter for a stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum 5052-H32	Magnesium AZ31B-H24
Stiff rod or tie (tension)	lighter	3% heavier
Stiff beam (bending)	21% heavier	lighter
Stiff panel or plate	31% heavier	lighter
Strong rod or tie	1.71x heavier	lighter
Strong beam	1.64x heavier	lighter
Strong panel or plate	1.61x heavier	lighter

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).

Thermal

Which conducts heat better, Aluminum 5052-H32 or Magnesium AZ31B-H24?

Aluminum 5052-H32 conducts heat better: 138 W/m·K against 76.9 W/m·K for Magnesium AZ31B-H24.

Which expands less with temperature?

Aluminum 5052-H32 expands less: 23.8 µm/m·K against 26.8 µm/m·K for Magnesium AZ31B-H24.