Titanium alloy Grade 36 is essentially niobium-titanium alloy. Its grade corresponds to UNS R58450, with a chemical composition of Ti-45Nb (approximately 55% titanium and 45% niobium), and it belongs to β -type niobium-titanium alloy. It plays a significant role in fields such as aviation and medical care, thanks to its excellent properties that balance strength and plasticity as well as outstanding corrosion resistance.
Grade 36 niobium-titanium alloy belongs to the field of superconducting materials rather than conventional structural materials. It is essentially different from the "titanium alloy" we usually discuss. Common titanium alloys (such as Ti-6Al-4V) are designed to achieve high strength and lightweight, while niobium-titanium alloys (Nb-Ti) are intended to obtain superconducting properties. Niobium-titanium alloy is an intermetallic compound that exhibits superconductivity at extremely low temperatures (liquid helium temperature, 4.2K, that is, -269°C). The most common component is Nb-47wt.%Ti (containing approximately 47% of titanium by weight), which is also the most important superconducting material in practical applications.
Its main component is Nb-47wt.%Ti. Different "grades" may have different control requirements for impurity elements such as oxygen, nitrogen, carbon, and iron, and these impurities can seriously affect their superconducting performance. The maximum lossless current density that a superconductor can carry under specific temperature and magnetic field conditions. This is a key indicator for measuring the performance of superconducting materials. Grade 36 May represent an industrial grade with specific and optimized critical current density performance. The manufacturing of niobium-titanium alloy superconducting wires is an extremely complex and precise process, far more complicated than the production of ordinary metal wires. Its core objective lies in maximizing Jc through microstructure regulation. Pulling and deforming the material generates a large number of dislocations and grain boundaries within the Nb-Ti alloy. This "deformation-aging" cycle repeats dozens or even hundreds of times, eventually forming dense lattice defects and precipitated phases within the material. These structures act as magnetic flux binding centers, effectively "locking" the magnetic flux lines in place, thereby allowing large superconducting currents to pass through without resistance and greatly enhancing Jc.
Grade 36 has excellent hot working performance in forming and processing. The optimal hot rolling temperature is 750-800 ℃. At this temperature, the performance of the bars processed into wires fully meets the standards. It has good cold working plasticity and can be easily processed into various forms such as bars, plates, tubes and wires, meeting the customized requirements of different scenarios. Welding and heat treatment: Tungsten gas shielded welding can be adopted during welding, which is specified as ERTi-36 welding material in the AWS A5.16 standard; As it is a single-phase β alloy, no additional heat treatment is required after welding to maintain stable performance. The overall processing does not require complex techniques and has a relatively high forming efficiency.
Grade 36 of niobium-titanium alloy is a specific grade in the superconducting materials industry, and its composition is Nb-47Ti. It is not a structural material but a functional one. Its value lies in its ability to transmit huge currents without loss at the temperature of liquid helium, thereby generating a strong magnetic field. It is an indispensable cornerstone material for modern medicine (MRI) and cutting-edge physical science research (such as nuclear fusion and particle physics).
