Screening for O phase in advanced ?–TiAl alloys

This is a screening study using high-energy X-ray diffraction measurements to determine whether an orthorhombic phase forms in ?-based TiAl alloys of different compositions. The 13 alloy compositions investigated were chosen be either close commercial or identify the effects single alloying elements on formation phase. O with Cmcm structure was found several those ?-TiAl after aging heat treatment at 550 °C for 20 h. presence ?-stabilising such as niobium, tantalum, molybdenum vanadium did promote phase, while micro carbon boron neutral this respect. Furthermore, limit aluminium also found, below which formed investigated. lies between 46 at.% and 47 at.%.