Menu (ESC)

Grade 705C Cast Zirconium

Grade 705C zirconium is a zirconium alloy. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. It has a moderately low ductility and a moderately high tensile strength among zirconium alloys.

The graph bars on the material properties cards below compare grade 705C zirconium 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

Brinell Hardness


Elastic (Young's, Tensile) Modulus

98 GPa 14 x 106 psi

Elongation at Break

13 %

Poisson's Ratio


Rockwell B Hardness


Shear Modulus

36 GPa 5.3 x 106 psi

Tensile Strength: Ultimate (UTS)

540 MPa 78 x 103 psi

Tensile Strength: Yield (Proof)

390 MPa 57 x 103 psi

Thermal Properties

Latent Heat of Fusion

250 J/g

Specific Heat Capacity

270 J/kg-K 0.064 BTU/lb-°F

Thermal Conductivity

18 W/m-K 10 BTU/h-ft-°F

Thermal Expansion

5.7 µm/m-K

Otherwise Unclassified Properties


6.7 g/cm3 420 lb/ft3

Embodied Water

450 L/kg 54 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

66 MJ/m3

Resilience: Unit (Modulus of Resilience)

790 kJ/m3

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

9.9 mm2/s

Thermal Shock Resistance

69 points

Alloy Composition

Zirconium (Zr)Zr 91.9 to 98
Niobium (Nb)Nb 2.0 to 3.0
Hafnium (Hf)Hf 0 to 4.5
Iron (Fe)Fe 0 to 0.3
Oxygen (O)O 0 to 0.3
Carbon (C)C 0 to 0.1
Nitrogen (N)N 0 to 0.030
Phosphorus (P)P 0 to 0.010
Hydrogen (H)H 0 to 0.0050

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

Followup Questions

Similar Alloys

Further Reading

ASTM B752: Standard Specification for Castings, Zirconium-Base, Corrosion Resistant, for General Application