Applications for niobium

Niobium consumption is dominated by its use as additive to high strength low alloy steel and stainless steel for oil and gas pipelines, car and truck bodies, architectural requirements, tool steels, ships hulls, railroad tracks. However, there are a number of other applications for niobium metal and its compounds.

Although niobium has many applications the majority is used in the production of high-grade structural steel. The second largest application for niobium is in nickel-based superalloys.

Some more unusual applications

Quantum computer chips (qubits)

Quantum computers being developed by IBM at its Q laboratory rely on superconducting qubits made from aluminum and niobium that sit atop a silicon substrate (the two superconducting electrodes sit between an insulator – or Josephson junction – of aluminum oxide). As opposed to classical computers, which use binary digits (bits) that can have one of two states (0 or 1) at a time to solve mathematical and logical operations, a quantum computer uses quantum bits which can have two states simultaneously. It follows that two qubits can hold four values at once (00, 01, 10, and 11), three qubits can hold eight values and so forth, thereby creating a system that's exponentially more powerful than a classic computer.  IBM's machines must be kept in total darkness in temperatures of 50 millikelvin (-272.78^oC) to operate.  IBM's most advanced research quantum computer operates a 50 qubit system, although a 20 qubit model can be rented for research purposes. In both the 50- and the 20-qubit systems, the quantum state is preserved for just 90 microseconds. Further information is available here.

High-entropy alloys (HEAs)

An alloy of tantalum, niobium, hafnium, zirconium and titanium has been shown to conduct electricity with zero resistance, or superconduct, from ambient pressure up to pressures similar to those that exist near the centre of the Earth. The material is a member of a new family of metal alloys known as high-entropy alloys (HEAs), which are composed of random atomic-scale mixtures of elements from the block of "transition metals" on the periodic table. HEAs have simple crystal structures, but the metals are arranged randomly on the lattice points, giving each alloy the properties of a both a glass and a crystalline material. The HEA studied in this work is unique in that it can superconduct continuously from low to high pressures. This discovery was made by a group of scientists from the Institute of Physics at the Chinese Academy of Sciences and the Chemistry Department at Princeton University. Further information is available here.

Gravimeters

Gravimeters measure changes in the Earth's gravity. Near the town of Membach, Belgium, is an exceptionally accurate superconducting gravimeter that uses a small sphere of niobium metal suspended in a magnetic field at below -263^oC (9.2 K), close to absolute zero. Any fluctuations in the gravitational field pull and tug on the sphere, shifting its position ever so slightly, perturbing the magnetic field and sending electrical signals to nearby sensors. At 9.2 K niobium reaches its superconducting transition temperature and magnetic field lines flow around, rather than through, the sphere, keeping it suspended in the centre of its little chamber. Niobium wire coils, also kept at this low temperature, offer no resistance to the electrical current that flows through them, producing the perfectly stable magnetic field that levitates the niobium sphere. Before niobium superconductors were developed older gravimeters used reference weights attached to mechanical springs. Further information is available here.

Orthopedic implants

Titanium niobium nitride (Ti-Nb-N) is a hard surface modification which has been in use in Europe for over ten years to offer protection against wear and allergies in orthopedic applications such as artificial knees. TiNbN acts like a physical barrier against the corrosion process and the metallic ions release towards the surrounding biologic environment, thus, making TiNbN-coated prostheses possible to be safety implanted in metal sensitized patient.

Titanium-zirconium-niobium alloys (Ti-Zr-Nb) have potential to be used for solid and durable implants that are fully compatible with the human body. Ti-Zr-Nb alloys possess a high functional complex and so-called «superelasticity» (able to restore the original shape against large and repeated deformation). According to scientists, these alloys are the most promising class of metallic biomaterials. This is due to the unique combination of their biochemical and biomechanical properties: Ti-Zr-Nb differs from the complete biocompatibility of composition and high corrosion resistance, while at the same time exhibiting hyperelastic behavior - very similar to «normal» bone behavior. NUST MISIS scientists jointly with their colleagues from the Ecole de Technologie Superiore (Montreal, Canada) are using this material to develop an industrial technology for the production of metal rod stocks which are used in the production of modern bone implants, and in particular, for treatment of spinal problems.