Applicability and Performance Benefits of XD (Tradename) Titanium Aluminides toExpendable Gas Turbine Engines

摘要

The purpose of this program was to produce XD-TiAl compressor rotors for theexperimental P9005 gas turbine engine to be used in the Army's Integrated High Performance Turbine Engine Technology program. Specific tasks included the casting of XD-titanium aluminide, processing optimization, component design analysis modifications and final component machining to specifications. Specifically, an ingot of a Ti-45Al-2Mn-2V alloy containing 7 volume % TiB2 was cast and then HIPed to eliminate residual porosity. Eight cylinders were machined from the HIPed material and isothermally forged. Microstructural analysis and mechanical property evaluation were performed on representative forgings. Several heat treatment schedules were examined, and the resulting microstructures were characterized using x-ray diffraction, optical and scanning electron microscopy. From these analyses, heat treatments were identified. Tensile behavior as a function of temperature, fracture toughness at room and elevated temperatures, creep resistance and fatigue response were evaluated. Fracture surfaces were characterized. Based on the observed mechanical properties, heat-treatment schedules were identified for the remaining forgings intended to be machined into final components. Williams International performed a detailed design analysis for the rotor. A local vendor was identified to machine the final component. XD Process, Titanium aluminide, Titanium diboride, Composites, Microstructure, Processing, Properties.