Investigation of operational characteristics of special-purpose alloy castings

Abstract

Pilot smeltings of the intermetallic titanium alloy are performed during the work in the vacuum induction smelting installation with a “cold crucible” and the blades of a gas-turbine engine are fabricated by the casting method according to investment models in the centrifugal field. The structure of the initial charge billet for casting the intermetallic titanium alloy is investigated and its chemical composition is analyzed. The process parameters of casting and results of metallographic analysis of fabricated blades are presented. It is established that the cast blade structure has a lamellar structure and consists of phases γ and α₂. The results of testing mechanical properties are presented. It is established that ultimate tensile strength σ_B = 765 MPa, yield point σ_y = 726.5 MPa, and relative elongation δ = 1.6%. The stress distribution on the blade pen is investigated and its distribution diagrams are constructed. Blade samples are tested for long-term strength (t = 650°C, τ = 500 h), fatigue strength, and impact toughness.