# Titanium 6-7 (R56700)

Titanium 6-7 is a titanium alloy formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. R56700 is the UNS number for this material. Titanium 6-7 is the common industry name.

It has the highest base cost among wrought titaniums. In addition, it has a fairly high density and a fairly high melting temperature.

The graph bars on the material properties cards below compare titanium 6-7 to: wrought titaniums (top), all titanium alloys (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

120 *GPa* 17 *x 10 ^{6} psi*

Elongation at Break

11 *%*

Fatigue Strength

530 *MPa* 77 *x 10 ^{3} psi*

Poisson's Ratio

0.33

Reduction in Area

29 *%*

Shear Modulus

45 *GPa* 6.5 *x 10 ^{6} psi*

Shear Strength

610 *MPa* 88 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

1020 *MPa* 150 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

900 *MPa* 130 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

410 *J/g*

Maximum Temperature: Mechanical

300 *°C* 580 *°F*

Melting Completion (Liquidus)

1700 *°C* 3100 *°F*

Melting Onset (Solidus)

1650 *°C* 3000 *°F*

Specific Heat Capacity

520 *J/kg-K* 0.13 *BTU/lb-°F*

Thermal Expansion

9.3 *µm/m-K*

## Otherwise Unclassified Properties

Base Metal Price

75 *% relative*

Density

5.1 *g/cm ^{3}* 320

*lb/ft*

^{3}Embodied Carbon

34 *kg CO _{2}/kg material*

Embodied Energy

540 *MJ/kg* 230 *x 10 ^{3} BTU/lb*

Embodied Water

190 *L/kg* 23 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

110 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

3460 *kJ/m ^{3}*

Stiffness to Weight: Axial

13 *points*

Stiffness to Weight: Bending

32 *points*

Strength to Weight: Axial

56 *points*

Strength to Weight: Bending

44 *points*

Thermal Shock Resistance

66 *points*

## Alloy Composition

Ti | 84.9 to 88 | |

Mo | 6.5 to 7.5 | |

Nb | 6.5 to 7.5 | |

Al | 5.5 to 6.5 | |

Ta | 0 to 0.5 | |

Fe | 0 to 0.25 | |

O | 0 to 0.2 | |

C | 0 to 0.080 | |

N | 0 to 0.050 | |

H | 0 to 0.0090 |

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

## Followup Questions

## Similar Alloys

## Further Reading

ASTM F1295: Standard Specification for Wrought Titanium-6 Aluminum-7 Niobium Alloy for Surgical Implant Applications (UNS R56700)

Titanium and Titanium Alloys: Fundamentals and Applications, Christoph Leyens and Manfred Peters (editors), 2003

Titanium, 2nd ed., G. Lutjering and J. C. Williams, 2007

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