Resource-Saving Technology of Manufacturing of Semifinished Products from Intermetallic γ-TiAl Alloys Intended for Aviation Engineering

Abstract

We develop an integrated resource-saving technology of manufacturing of semifinished products from γ -TiAl intermetallic alloys intended for aviation engineering and, in particular, for compressor blades. We describe the structure of an absolutely new, as compared with the existing procedures, technology of manufacturing of semifinished products from alloys based on titanium aluminide characterized by low prime cost and improved mechanical properties. For this purpose, we apply and combine the methods of self-propagating high-temperature synthesis (SHS) and severe plastic deformation (SPD) of source blanks. It is shown that the developed compositions of SHS mixtures and the technological conditions of the SHS-process make it possible to create γ -TiAl intermetallic alloys whose chemical and phase compositions are not inferior to the level of the best foreign analogs for a much lower relative prime cost of production. In the next stage of the technological process, the blanks are subjected to complex SPD, which makes it possible to remove the main disadvantages typical of SHS procedure, namely, the structural heterogeneity, residual porosity, and low plasticity. This is explained by the main effects of the SPD procedure (mass transfer and mixing of the material), which lead to the homogenization of the alloy, grinding of grains, and the formation of submicrocrystalline structure of the material.