# Spring-Tempered ASTM B780 Silver-Copper-Nickel Alloy

Spring-tempered ASTM B780 alloy is ASTM B780 alloy in the spring temper. It has the highest strength and lowest ductility compared to the other variants of ASTM B780 alloy.

The graph bars on the material properties cards below compare spring-tempered ASTM B780 alloy to: precious metal electrical contact alloys (top), all alloys in the same category (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

## Mechanical Properties

Elastic (Young's, Tensile) Modulus

83 *GPa* 12 *x 10 ^{6} psi*

Elongation at Break

1.1 *%*

Fatigue Strength

280 *MPa* 41 *x 10 ^{3} psi*

Poisson's Ratio

0.36

Shear Modulus

30 *GPa* 4.4 *x 10 ^{6} psi*

Shear Strength

340 *MPa* 49 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

590 *MPa* 86 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

460 *MPa* 66 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

140 *J/g*

Melting Completion (Liquidus)

860 *°C* 1580 *°F*

Specific Heat Capacity

270 *J/kg-K* 0.065 *BTU/lb-°F*

Thermal Expansion

18 *µm/m-K*

## Other Material Properties

Density

10 *g/cm ^{3}* 630

*lb/ft*

^{3}Electrical Conductivity: Equal Volume

70 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

62 *% IACS*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

6.2 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

1250 *kJ/m ^{3}*

Stiffness to Weight: Axial

4.5 *points*

Stiffness to Weight: Bending

14 *points*

Strength to Weight: Axial

16 *points*

Strength to Weight: Bending

15 *points*

Thermal Shock Resistance

29 *points*

## Alloy Composition

Ag | 74 to 76 | |

Cu | 23.5 to 25.7 | |

Ni | 0.35 to 0.65 | |

Zn | 0 to 0.060 | |

Fe | 0 to 0.050 | |

Cd | 0 to 0.050 | |

Pb | 0 to 0.030 |

All values are % weight. Ranges represent what is permitted under applicable standards.

## Followup Questions

## Further Reading

ASTM B780: Standard Specification for 75% Silver, 24.5% Copper, 0.5% Nickel Electrical Contact Alloy