Annealed ASTM B780 Alloy vs. Annealed R31538 Cobalt

Annealed ASTM B780 alloy belongs to the otherwise unclassified metals classification, while annealed R31538 cobalt belongs to the cobalt alloys. There are 17 material properties with values for both materials. Properties with values for just one material (13, in this case) are not shown.

For each property being compared, the top bar is annealed ASTM B780 alloy and the bottom bar is annealed R31538 cobalt.

Annealed ASTM B780 Silver-Copper-Nickel Alloy Annealed High Carbon Co-28Cr-6Mo Alloy

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa		83
Elastic (Young's, Tensile) Modulus, GPa		220

Elongation at Break, %		9.1
Elongation at Break, %		23

Poisson's Ratio		0.36
Poisson's Ratio		0.29

Shear Modulus, GPa		30
Shear Modulus, GPa		86

Tensile Strength: Ultimate (UTS), MPa		330
Tensile Strength: Ultimate (UTS), MPa		1020

Thermal Properties

Latent Heat of Fusion, J/g		140
Latent Heat of Fusion, J/g		320

Melting Completion (Liquidus), °C		860
Melting Completion (Liquidus), °C		1360

Specific Heat Capacity, J/kg-K		270
Specific Heat Capacity, J/kg-K		450

Thermal Expansion, µm/m-K		18
Thermal Expansion, µm/m-K		13

Electrical Properties

Electrical Conductivity: Equal Volume, % IACS		76
Electrical Conductivity: Equal Volume, % IACS		2.0

Electrical Conductivity: Equal Weight (Specific), % IACS		68
Electrical Conductivity: Equal Weight (Specific), % IACS		2.1

Otherwise Unclassified Properties

Density, g/cm³		10
Density, g/cm³		8.4

Common Calculations

Stiffness to Weight: Axial, points		4.5
Stiffness to Weight: Axial, points		15

Stiffness to Weight: Bending, points		14
Stiffness to Weight: Bending, points		24

Strength to Weight: Axial, points		9.1
Strength to Weight: Axial, points		34

Strength to Weight: Bending, points		11
Strength to Weight: Bending, points		27

Thermal Shock Resistance, points		16
Thermal Shock Resistance, points		25

Alloy Composition

Cadmium (Cd), %		0 to 0.050
Cadmium (Cd), %		0

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

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

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

Copper (Cu), %		23.5 to 25.7
Copper (Cu), %		0

Iron (Fe), %		0 to 0.050
Iron (Fe), %		0 to 0.75

Lead (Pb), %		0 to 0.030
Lead (Pb), %		0

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

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

Nickel (Ni), %		0.35 to 0.65
Nickel (Ni), %		0 to 1.0

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

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

Silver (Ag), %		74 to 76
Silver (Ag), %		0

Zinc (Zn), %		0 to 0.060
Zinc (Zn), %		0