R31538 Cobalt vs. R05240 Alloy

R31538 cobalt belongs to the cobalt alloys classification, while R05240 alloy belongs to the otherwise unclassified metals. There are 18 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown.

For each property being compared, the top bar is R31538 cobalt and the bottom bar is R05240 alloy.

High Carbon Co-28Cr-6Mo Alloy (ASTM F1537 Alloy 2, ISO 5832-12 Alloy 2, R31538)UNS R05240 Tantalum-Niobium Alloy

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa		220
Elastic (Young's, Tensile) Modulus, GPa		150

Elongation at Break, %		13 to 23
Elongation at Break, %		25

Poisson's Ratio		0.29
Poisson's Ratio		0.36

Shear Modulus, GPa		86
Shear Modulus, GPa		57

Tensile Strength: Ultimate (UTS), MPa		1020 to 1360
Tensile Strength: Ultimate (UTS), MPa		270

Tensile Strength: Yield (Proof), MPa		580 to 930
Tensile Strength: Yield (Proof), MPa		170

Thermal Properties

Latent Heat of Fusion, J/g		320
Latent Heat of Fusion, J/g		210

Specific Heat Capacity, J/kg-K		450
Specific Heat Capacity, J/kg-K		190

Thermal Expansion, µm/m-K		13
Thermal Expansion, µm/m-K		6.8

Otherwise Unclassified Properties

Density, g/cm³		8.4
Density, g/cm³		14

Embodied Water, L/kg		530
Embodied Water, L/kg		460

Common Calculations

Resilience: Ultimate (Unit Rupture Work), MJ/m³		140 to 200
Resilience: Ultimate (Unit Rupture Work), MJ/m³		59

Resilience: Unit (Modulus of Resilience), kJ/m³		750 to 1920
Resilience: Unit (Modulus of Resilience), kJ/m³		90

Stiffness to Weight: Axial, points		15
Stiffness to Weight: Axial, points		6.3

Stiffness to Weight: Bending, points		24
Stiffness to Weight: Bending, points		13

Strength to Weight: Axial, points		34 to 45
Strength to Weight: Axial, points		5.4

Strength to Weight: Bending, points		27 to 32
Strength to Weight: Bending, points		6.8

Thermal Shock Resistance, points		25 to 33
Thermal Shock Resistance, points		18

Alloy Composition

Carbon (C), %		0.15 to 0.35
Carbon (C), %		0 to 0.010

Chromium (Cr), %		26 to 30
Chromium (Cr), %		0

Cobalt (Co), %		58.7 to 68.9
Cobalt (Co), %		0

Hydrogen (H), %		0
Hydrogen (H), %		0 to 0.0015

Iron (Fe), %		0 to 0.75
Iron (Fe), %		0 to 0.010

Manganese (Mn), %		0 to 1.0
Manganese (Mn), %		0

Molybdenum (Mo), %		5.0 to 7.0
Molybdenum (Mo), %		0 to 0.020

Nickel (Ni), %		0 to 1.0
Nickel (Ni), %		0 to 0.010

Niobium (Nb), %		0
Niobium (Nb), %		35 to 42

Nitrogen (N), %		0 to 0.25
Nitrogen (N), %		0 to 0.010

Oxygen (O), %		0
Oxygen (O), %		0 to 0.020

Silicon (Si), %		0 to 1.0
Silicon (Si), %		0 to 0.0050

Tantalum (Ta), %		0
Tantalum (Ta), %		57.9 to 65

Titanium (Ti), %		0
Titanium (Ti), %		0 to 0.010

Tungsten (W), %		0
Tungsten (W), %		0 to 0.050