# Grade 7 (3.7235, R52400) Titanium

Grade 7 titanium is a titanium alloy formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. 3.7235 is the EN numeric designation for this material. R52400 is the UNS number. Additionally, the ASTM designation is Titanium Grade 7.

It has a moderately high thermal conductivity among wrought titaniums. In addition, it has a fairly high embodied energy and a moderately high ductility.

The graph bars on the material properties cards below compare grade 7 titanium 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

Brinell Hardness

150

Elastic (Young's, Tensile) Modulus

110 *GPa* 15 *x 10 ^{6} psi*

Elongation at Break

24 *%*

Fatigue Strength

250 *MPa* 36 *x 10 ^{3} psi*

Poisson's Ratio

0.32

Reduction in Area

34 *%*

Shear Modulus

38 *GPa* 5.5 *x 10 ^{6} psi*

Shear Strength

270 *MPa* 39 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

420 *MPa* 61 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

340 *MPa* 50 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

420 *J/g*

Maximum Temperature: Mechanical

320 *°C* 600 *°F*

Melting Completion (Liquidus)

1660 *°C* 3020 *°F*

Melting Onset (Solidus)

1610 *°C* 2930 *°F*

Specific Heat Capacity

540 *J/kg-K* 0.13 *BTU/lb-°F*

Thermal Conductivity

22 *W/m-K* 13 *BTU/h-ft-°F*

Thermal Expansion

9.2 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

3.6 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

7.2 *% IACS*

## Otherwise Unclassified Properties

Density

4.5 *g/cm ^{3}* 280

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

800 *MJ/kg* 340 *x 10 ^{3} BTU/lb*

Embodied Water

470 *L/kg* 56 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

95 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

560 *kJ/m ^{3}*

Stiffness to Weight: Axial

13 *points*

Stiffness to Weight: Bending

35 *points*

Strength to Weight: Axial

26 *points*

Strength to Weight: Bending

28 *points*

Thermal Diffusivity

8.9 *mm ^{2}/s*

Thermal Shock Resistance

31 *points*

## Alloy Composition

Ti | 98.7 to 99.88 | |

Pd | 0.12 to 0.25 | |

Fe | 0 to 0.3 | |

O | 0 to 0.25 | |

C | 0 to 0.080 | |

N | 0 to 0.030 | |

H | 0 to 0.015 | |

res. | 0 to 0.4 |

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

## Followup Questions

## Similar Alloys

## Further Reading

ASTM B861: Standard Specification for Titanium and Titanium Alloy Seamless Pipe

ASTM B381: Standard Specification for Titanium and Titanium Alloy Forgings

ASTM B265: Standard Specification for Titanium and Titanium Alloy Strip, Sheet, and Plate

ASTM B348: Standard Specification for Titanium and Titanium Alloy Bars and Billets

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

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

Aerospace Materials, Brian Cantor et al. (editors), 2001

Environmental Degradation of Advanced and Traditional Engineering Materials, Lloyd H. Hihara et al., 2014.

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