# UNS R60705 Zirconium-Niobium Alloy

R60705 alloy is a zirconium alloy. Cited properties are appropriate for the annealed condition. It has a moderately low thermal conductivity and a moderately high tensile strength among zirconium alloys.

The graph bars on the material properties cards below compare R60705 alloy to: zirconium 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

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

Elongation at Break

18 *%*

Fatigue Strength

290 *MPa* 42 *x 10 ^{3} psi*

Poisson's Ratio

0.34

Shear Modulus

37 *GPa* 5.3 *x 10 ^{6} psi*

Tensile Strength: Ultimate (UTS)

540 *MPa* 78 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

430 *MPa* 63 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

250 *J/g*

Specific Heat Capacity

270 *J/kg-K* 0.064 *BTU/lb-°F*

Thermal Conductivity

17 *W/m-K* 9.9 *BTU/h-ft-°F*

Thermal Expansion

6.3 *µm/m-K*

## Otherwise Unclassified Properties

Density

6.7 *g/cm ^{3}* 420

*lb/ft*

^{3}Embodied Water

450 *L/kg* 54 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

90 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

950 *kJ/m ^{3}*

Stiffness to Weight: Axial

8.1 *points*

Stiffness to Weight: Bending

23 *points*

Strength to Weight: Axial

22 *points*

Strength to Weight: Bending

22 *points*

Thermal Diffusivity

9.5 *mm ^{2}/s*

Thermal Shock Resistance

63 *points*

## Alloy Composition

Zr | 91 to 98 | |

Nb | 2.0 to 3.0 | |

Hf | 0 to 4.5 | |

Cr | 0 to 0.2 | |

Fe | 0 to 0.2 | |

O | 0 to 0.18 | |

C | 0 to 0.050 | |

N | 0 to 0.025 | |

H | 0 to 0.0050 |

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

## Followup Questions

## Similar Alloys

## Further Reading

ASTM B493: Standard Specification for Zirconium and Zirconium Alloy Forgings

ASTM B523: Standard Specification for Seamless and Welded Zirconium and Zirconium Alloy Tubes

ASTM B550: Standard Specification for Zirconium and Zirconium Alloy Bar and Wire

ASTM B658: Standard Specification for Seamless and Welded Zirconium and Zirconium Alloy Pipe

ASTM B551: Standard Specification for Zirconium and Zirconium Alloy Strip, Sheet, and Plate

Extractive Metallurgy of Niobium, C. K. Gupta and A. K. Suri, 1993

Sintering of Advanced Materials: Fundamentals and Processes, Zhigang Zak Fang (editor), 2010