Low density niobium alloy

Low density niobium alloy, also known as light niobium alloy, is by adding tungsten, molybdenum, chromium, titanium, aluminium, zirconium, carbon, vanadium and other elements formed at the same time with solid solution strengthening and precipitation strengthening of a class of niobium alloy. Due to the addition of a large number of light elements such as Ti and Al, the density of this kind of alloy is generally 5.9-6.9g·cm-3, which is lighter than niobium C103 and Nb521 alloys. These alloys also have good mechanical properties and machining properties at room temperature and high temperature, and can be forged, rolled, spun and stamped. At the same time, this kind of alloy can be used in the atmosphere of 550 ~ 800 ℃ without coating, and can be used in the atmosphere of 800 ~ 1300 ℃ after coating. Dozens of low-density niobium alloys, including Nb-Ti-Al, Nb-Ti-Al-Hf and Nb-Ti-Al-V systems, have been developed in the United States and other countries. Abroad, low-density niobium alloys have been used in rocket and aero-engine heating components, such as Pratt-Whitney military aircraft engine exhaust pipes, Russian jet heat exchange lines and new ramjet thermal structural components. Current problems of low density niobium alloy:

1) The addition of Si, Ti, Al and other strengthening elements in the alloy has a great influence on the plasticity of the alloy at room temperature, increasing the difficulty of deformation processing of the alloy, especially in the production of large size processing materials.

2) Although the alloy has a certain oxidation resistance, it still needs to be coated with oxidation resistance coating when used at 1200℃. At present, there are few researches on low density niobium alloy in China, and it is still stuck in the stage of preparing aluminide by embedding infiltration method and silicide coating by slurry melting method, and the properties are low, so it is necessary to strengthen the research on coating.