NB6966 Nickel Niobium Master Alloy

Nickel Niobium Master Alloy Description

Nickel Niobium Master Alloy (NiNb) comprises 60–65% niobium and 35–40% nickel. Its impurity limits are strictly controlled: Fe ≤0.5%, Al/Si ≤0.1%, C ≤0.05% and O ≤0.15%. It is used as an additive in nickel‐based superalloys. During ageing heat treatments, it produces gamma‐double‐prime (γ'') precipitates (Ni₃Nb). The disk‐shaped precipitates measure 10–50 nm in diameter. They obstruct dislocation motion and yield a measured strength above 1 000 MPa at 700°C. They also deliver a rupture life exceeding 500 hours at 750°C/300 MPa. The low oxygen content reduces oxide inclusion formation, thereby ensuring microstructural homogeneity. This homogeneity is critical for fatigue resistance during thermal cycling (e.g. 10⁴ cycles at 800°C). NiNb‐modified superalloys develop oxidation stability through chromia‐alumina scales. These scales reduce hot corrosion and sulfidation in jet engine exhaust environments. Niobium increases thermal conductivity to 12 W/m·K at 800°C. It also maintains an elongation of 15–20% via refined grain boundaries. The alloy melts between 1 350°C and 1 450°C and dissolves uniformly in superalloy melts. Its Nb/Ni ratio ensures complete γ'' precipitation and prevents brittle Laves phase formation. It is applied in Inconel 718 turbine discs, nuclear reactor fuel cladding and rocket thrust chambers. NiNb stabilises microstructures against coarsening up to 850°C. Consequently, it extends service life by a factor of 3–5 compared with conventional alloys.

Nickel Niobium Master Alloy Applications

NiNb (60–65% Nb, 35–40% Ni) is used in aerospace superalloys such as Inconel 718. In ageing treatments, it forms gamma‐double‐prime (γ'') precipitates (Ni₃Nb). The precipitates provide a measured strength above 1 000 MPa at 700°C, a rupture life exceeding 500 hours at 750°C/300 MPa and stable oxidation properties. They are used in jet engine turbine discs, combustor liners and rocket nozzles. In energy infrastructure, NiNb improves nuclear reactor fuel cladding and gas turbine blades. It resists radiation‐induced damage and thermal fatigue. NiNb‐modified powders are used in additive manufacturing for 3D‐printed components that require microstructural stability above 800°C.

Nickel Niobium Master Alloy Packaging

Our products are packaged in customised cartons. The carton size depends on the material dimensions. Small items are packed in PP boxes. Larger items are placed in custom wooden crates. We adhere to packaging customisation and use suitable cushioning materials. This method ensures protection during transportation.

Packaging: Carton, Wooden Box, or Customized.

Kindly review the packaging details provided for your reference.

Manufacturing Process

1.       Testing Method

(1)    Chemical Composition Analysis – The chemical composition is determined using GDMS or XRF. This check ensures that impurity levels meet specifications.

(2)    Mechanical Properties Testing – Tensile strength, yield strength and elongation are measured. These tests assess material performance.

(3)    Dimensional Inspection – Thickness, width and length are measured. The dimensions are compared with specified tolerances.

(4)    Surface Quality Inspection – Defects such as scratches, cracks or inclusions are inspected. Visual and ultrasonic examinations are performed.

(5)    Hardness Testing – Hardness is measured. This confirms uniformity and mechanical reliability.

Please refer to the Stanford Advanced Materials (SAM) testing procedures for detailed information.

Nickel Niobium Master Alloy FAQs

Q1. Why use NiNb instead of pure niobium?

NiNb has a nickel matrix that dissolves in superalloy melts in a controlled manner. This process prevents niobium vaporisation and ensures complete γ'' precipitation. Pure niobium may segregate and react incompletely.

Q2. Optimal addition rate?

The typical addition rate is 2–5 wt% in nickel superalloys. An addition of more than 5 wt% niobium may lead to the formation of brittle Laves phases (e.g. NbNi₃).

Q3. Impurity limits?

Impurity limits are defined as follows: oxygen ≤0.15%, carbon ≤0.05% and sulphur/phosphorous ≤0.02%. These limits prevent oxide inclusions, carbide brittleness and hot cracking.

Related Information

1.       Common Preparation Methods

NiNb is produced by vacuum induction melting (VIM) or by aluminothermic reduction:

VIM Process: High-purity niobium (99.95%) and electrolytic nickel are loaded into an MgO crucible under argon. The charge is induction-heated to 1 600–1 650°C and homogenised for 2–4 hours. The molten alloy is then cast into ingots. Rapid cooling at a rate below 100°C/min suppresses niobium segregation.

Aluminothermic Reduction: A blend of Nb₂O₅ concentrate, nickel oxide (NiO) and aluminium powder is ignited in a refractory reactor. The exothermic reaction reaches 2 200°C and reduces the oxides to a molten alloy containing 60–65% niobium with less than 0.15% oxygen. After cooling, the slag (Al₂O₃) is removed.

Final processing steps include crushing the alloy into 10–50 mm lumps and performing magnetic separation to remove slag residues.