Grade 705 Zirconium (Zr-2.5Nb) Technical Data Sheet
Alloy Overview
Grade 705 Zirconium (Zr-2.5Nb) is a zirconium-niobium alloy with 2.5% niobium (Nb) as the primary alloying element, complemented by controlled levels of iron (Fe), chromium (Cr), hafnium (Hf), and oxygen (O). It is engineered to deliver enhanced mechanical strength compared to related grades, while retaining zirconium’s inherent corrosion resistance. The minimum zirconium content is 95.5% (including a maximum of 4.5% hafnium).
Chemical Composition (Weight %)
Component
Content Range
Zr (Zr + Hf)
Min 95.5 (balance)
Nb
2.5
Fe + Cr
0.2
Hf
Max 4.5
O
0.18
Physical Properties
Property
Metric
English
Density
6.44 g/cc
0.233 lb/in³
四、Mechanical Properties
Property
Metric
English
Notes
Tensile Strength (Ultimate)
Min 552 MPa
Min 80,100 psi
Tensile Strength (Yield, 0.2%)
Min 379 MPa
Min 55,000 psi
0.2% offset
Elongation at Break
16%
16%
Measured in 50 mm
Modulus of Elasticity
97.9 GPa
14,200 ksi
Poisson’s Ratio
0.33
0.33
Shear Modulus
34.5 GPa
5,000 ksi
Electrical Properties
Property
Metric
English
Electrical Resistivity
5.5e-005 ohm-cm
5.5e-005 ohm-cm
Thermal Properties
Property
Metric
English
Notes
Linear CTE (20°C)
6.3 μm/m-°C
3.5 μin/in-°F
Measured at 25°C
Specific Heat Capacity
0.285 J/g-°C
0.0681 BTU/lb-°F
Thermal Conductivity
17.1 W/m-K
119 BTU-in/hr-ft²-°F
Melting Point
1840°C
3340°F
Key Features & Applications
Enhanced Strength: Higher tensile and yield strengths compared to grades with lower oxygen content, making it suitable for structural components under moderate to high stress.
Corrosion Resistance: Maintains zirconium’s excellent resistance to aggressive media (e.g., acids, high-temperature water), ideal for chemical processing and nuclear industries.
Typical Uses: Pressure vessels, heat exchangers, and piping in corrosive environments, as well as components requiring a balance of strength and durability.
