Materials / Compare

Magnesium AZ91D vs. Rubber

Compare Magnesium AZ91D vs. Rubber strength, stiffness, weight and thermal properties.

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Magnesium AZ91DCast
RubberBulk polymer (molded or machined)
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Mechanical
Yield strength150MPasourcetypical, 0.2% tensile yield, ambient temperaturenot given (tensile used)
Ultimate tensile strength230MPasourcetypical, ambient temperature23MPasourcetypical
Elongation at break3%sourcetypical, ambient temperature830%sourcetypical
Young's modulus (stiffness)45GPasourcetypicalnot sourced
Density1,810kg/m³sourcetypical960kg/m³sourcetypical (specific gravity)
Strength to weight82.9kN·m/kg3.46x higher24kN·m/kg
Stiffness to weight24.9MN·m/kgnot sourced
Poisson's ratio0.35sourcebase material: AZ91C casting (MIL-HDBK-5J handbook physical constant)0.5sourcegovernment (NBS J. Res. 68A, 1964): computed by NBS for peroxide-cured gum NR vulcanizate, 25 °C, infinitesimal deformation0.49 in the solver: the linear element locks as the ratio nears 0.5 (nearly incompressible).
Shear modulus16.7GPanot sourced
Bulk modulus50GPanot sourced
Speed of sound4,986m/snot sourced
Thermal
Thermal conductivity72W/m·Ksourcetypical0.151W/m·Ksourcegovernment selected value (US Army Natick Laboratories TR 66-49-PR, 1966), soft vulcanized natural rubber, 25 °C
Thermal expansion25µm/m·Ksourcetypical, temperature range not statednot sourced
100 mm part over a 50 °C swing125µm growthnot sourced
Specific heat1,050J/kg·Ksourcetypical1,881J/kg·Ksourcegovernment (NBS J. Res. 68A, Table 7; values observed for unvulcanized NR by Bekkedahl and Matheson), 25 °C
Heats up and cools (diffusivity)37.9mm²/s453x faster0.0836mm²/s
Thermal shock resistance6,240W/mnot sourced
Melting point470–595°Csourcemelting rangenot sourced
Max service temperaturenot sourced70°Csourcecontinuous use operating range
Values forELEKTRON AZ91D magnesium die-casting alloy, as cast; Magnesium Elektron datasheet 475 (7/01), typical properties; Poisson from MIL-HDBK-5J for AZ91C castings.Weir Minerals Linatex Premium rubber (95 % natural rubber), typical physical properties, spec sheet WMD0118/202305

Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Questions

Is Magnesium AZ91D stronger than Rubber?

Magnesium AZ91D is stronger: its yield strength is 150 MPa against tensile strength 23 MPa for Rubber (6.52x).

Which is lighter, Magnesium AZ91D or Rubber?

Rubber is lighter: 960 kg/m³ against 1,810 kg/m³ for Magnesium AZ91D.

Which is lighter for the same job, Magnesium AZ91D or Rubber?

For the same stiffness or strength: Magnesium AZ91D is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must beMagnesium AZ91DRubber
Strong rod or tielighter3.46x heavier
Strong beamlighter1.85x heavier
Strong panel or platelighter35% 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 conducts heat better, Magnesium AZ91D or Rubber?

Magnesium AZ91D conducts heat better: 72 W/m·K against 0.151 W/m·K for Rubber.

Among 72 materials

1k10k0.1110100Density (kg/m³)Young's modulus (GPa)Plastic PLAPlastic PETGPlastic ABSPlastic TPUPlastic NylonAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic PolycarbonatePlastic POM/AcetalPlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM PAHT-CFFDM HIPSSLA Resin Tough 2000SLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelPCB Laminate FR-4SiliconCeramic Alumina 96%Ceramic Aluminum NitrideAluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum ADC12Solder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Magnesium AZ91D
Stiffness against density
1k10k101001kDensity (kg/m³)Yield strength (MPa)Plastic PLAPlastic PETGPlastic ABSPlastic TPUPlastic NylonAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic PolycarbonatePlastic POM/AcetalPlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic PTFEPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM PAHT-CFFDM HIPSSLA Resin Tough 2000SLA Resin Elastic 50ASLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelBrickPCB Laminate FR-4SiliconCeramic Alumina 96%Aluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum ADC12Solder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Magnesium AZ91DRubber
Strength against density

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