# Work Hardened ASTM B522 Class II Gold-Silver-Platinum Alloy

Work hardened ASTM B522 class II is ASTM B522 class II in the cold worked (strain hardened) condition. The graph bars on the material properties cards below compare work hardened ASTM B522 class II 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

96 *GPa* 14 *x 10 ^{6} psi*

Elongation at Break

1.1 *%*

Knoop Hardness

150

Poisson's Ratio

0.41

Shear Modulus

34 *GPa* 5.0 *x 10 ^{6} psi*

Shear Strength

280 *MPa* 40 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

490 *MPa* 70 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

210 *MPa* 30 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

77 *J/g*

Melting Completion (Liquidus)

1030 *°C* 1890 *°F*

Melting Onset (Solidus)

1030 *°C* 1880 *°F*

Specific Heat Capacity

160 *J/kg-K* 0.037 *BTU/lb-°F*

Thermal Expansion

15 *µm/m-K*

## Other Material Properties

Density

17 *g/cm ^{3}* 1070

*lb/ft*

^{3}Electrical Conductivity: Equal Volume

11 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

5.7 *% IACS*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

4.4 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

230 *kJ/m ^{3}*

Stiffness to Weight: Axial

3.1 *points*

Stiffness to Weight: Bending

8.9 *points*

Strength to Weight: Axial

7.8 *points*

Strength to Weight: Bending

8.0 *points*

Thermal Shock Resistance

24 *points*

## Alloy Composition

Au | 68.5 to 69.5 | |

Ag | 24.5 to 25.5 | |

Pt | 5.5 to 6.5 | |

S | 0 to 0.010 | |

res. | 0 to 0.26 |

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

## Followup Questions

## Further Reading

ASTM B522: Standard Specification for Gold-Silver-Platinum Electrical Contact Alloy

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015