OPTIMIZATION OF INTERMETALLIC γ-TiAl ALLOY

Annotation. Purpose. Determination of compound influence on the mechanical properties (strength and plasticity) of intermetallic γ-TiAl alloy, and determination of its optimum composition. Methodology. The mechanical properties were determined on standard discontinuous specimens in accordance with GOST 1497-84 on a tearing machine MUP-20. Optimization parameters: Y1 - ultimate strength (σв), MPа → max; Y2 - relative elongation (δ),%. > 4. As independent variables, the content of niobium (X1), the content of molybdenum (X2), the content of the chromium mixture (X3) were chosen in the alloy. Findings. It is established the best combination of strength/ductility with the content of chemical elements (8.27Nb, 3.18Mo, 2Cr), which makes it possible to obtain an alloy with σs = 1200 MPa and δ = 4%. Recommended optimum composition of intermetallic γ-TiAl alloy, wt. %: aluminum - 30%, niobium - 8%, molybdenum - 5%, chromium - 1,7%, titanium - the rest. Originality. The regularities of the influence of alloying elements on the mechanical properties of intermetallic γ-TiAl alloys. Practical value. The calculations made allow us to recommend the following composition of intermetallic γ-TiAl alloy for practical use: Ti-44Al-4Nb-2Mo-1Cr.