Blog

Niobium alloys used for high-temperature structural parts are mainly divided into four categories: high-strength niobium alloys, medium-strength niobium alloys, low-strength niobium alloys and low-density niobium alloys. The strengthening methods of high-temperature silver alloys are divided into solid solution strengthening, solid solution strengthening and second phase strengthening. Pure niobium allows a large number of alloying elements to be solid dissolved in it. There are more than 50 types of alloy grades; the added solid solution strengthening elements include tungsten, molybdenum, tantalum, hafnium, vanadium, chromium, silicon, titanium, etc., while adding active elements such as titanium, zirconium, hafnium, yttrium and a certain proportion of gas gap elements carbon and oxygen to form a second phase of carbides and rare earth oxides for dispersion strengthen. High-, medium- and low-strength niobium alloys have excellent high-temperature creep and durability properties; they begin to oxidize violently at 500°C, and an anti-oxidation coating needs to be coated on the surface. The coating with better protection against silver alloys is Si-Cr- Silicide coatings such as Ti-Zr and Si-Mo-Zr-Hf-V series have excellent oxidation resistance and excellent thermal stability. Low-density niobium alloy does not require anti-oxidation coating and can work under 700~800℃ for a long time.

High-temperature niobium alloys are mainly prepared by vacuum electron beam melting, vacuum consumable arc melting, or a combination of vacuum electron beam melting and vacuum consumable arc melting. Ingots are usually cast by high-temperature extrusion, forging, and then through forging, Plastic processing methods such as rotary forging, rolling, and annealing produce rods, wires, plates, rings, and forgings. Methods of making various niobium alloy parts by pressing and sintering the ingot into niobium alloy powder have also been studied.

High-temperature niobium alloys are mainly used in aerospace, lighting and nuclear industries. Commonly used high temperature silver alloys are Nb-17r, C103 and Nb521 alloys. Nb-1Zr is used in liquid metal heat exchangers and cladding materials for nuclear reactors, arc tubes, leads, end caps of high-pressure sodium discharge lamps, injectors of aerospace liquid fuel, etc. C103, Nb521, SCb-291, and Fs-85 are used in various liquid rocket engine radiation cooling nozzles, combustion chambers, turbocharger dampers of turbo engines, etc. D43 is used for aerospace vehicle skins, and Nb752 is used for satellite antennas, aircraft honeycomb sandwich panels, and wing leading edges.