High temperature high performance high-niobium titanium-aluminium alloy

Abstract

A high-niobium Ti-Al alloy consists of Al 45-46 atoms%, Nb 8-10 atom%, C 0-0.2 atom%, W 0-0.2 atom%, Y 0-0.1 atom% and the remainder being Ti. The alloy texture consists of two ordered phases, i.e. gamma phase and alpha phase and has complete homogeneous and fine laminated texture with crystal grain size of 100-150 microns and interlamilar interval of 0.3-0.4 micron. The high-niobium Ti-Al alloy has the advantages of usage temperature as high as 840-900 deg.C.

Description

technical field [0001] The invention provides a high-temperature high-performance high-niobium-titanium aluminum alloy, which belongs to the technical field of high-temperature alloys. Background technique [0002] TiAl alloy has been recognized as the most promising intermetallic compound structural material. The TiAl composition range that has been developed is roughly, Ti-45 / 48Al-0 / 2M-0 / 5X-0 / 2Z (M=Cr, Mn, V, X=Nb, Ta, W, Z=Si, B , C, N), M-type alloying elements are conducive to plasticity and recrystallization, Nb, Ta are the main solid solution strengthening elements, a small amount of W and Sn also have similar effects, while Si, B, N, C precipitate the second phase Ti 5 Si 3 、Ti x AlC, etc. play a strengthening role, and B plays a role in refining grains, but it may increase the interlamellar spacing. At present, casting alloys have entered the stage of practical application, and their typical representatives are Ti-47 / 48Al-2Nb-2Cr (GE Company), Ti-47Al-2W-0.5Si ...

AI Technical Summary

Problems solved by technology

[0006] A high-strength powdered TiAl alloy has been studied abroad. The composition is the same as that of GE alloy. The grain and inter-sheet spacing are made very small (the inter-sheet spacing is less than 0.1 micron), and the strength of 1000MPa is obtained, but its high-temperature structure stability is insufficient.