Research On Mechanical Properties Of Deformed TiAl Alloy

TiAl alloy is the only light alloy material that can be used for a long time in an oxidizing environment above 600?,and its density is less than half of the traditional nickel-based superalloy.Because the first and second generation TiAl alloys have insufficient strength at650°C and cannot be applied to higher temperature turbine blades,the third generation TiAl alloy has become the focus of research.In this paper,the forged Ti42Al5Mn alloy and the forged TNM alloy are the research objects,and the mechanical behavior of the alloy at room temperature and high temperature and the influence of the heat treatment process on the structure and properties of the alloy are systematically studied.The main research results as follows:(1)Determine the ductile-brittle transition temperature range of Ti42Al5Mn wrought alloy and TNM alloy(2)The heat treatment process(1280?/30min/AC+950?/6h/FC)of Ti42Al5Mn alloy with fine equiaxed full lamella structure is formulated;the mechanical properties of deformed Ti42Al5Mn alloy at 600?and 650?are effectively improved,The yield strength has reached more than 600MPa.(3)After the deformed TNM alloy is heat treated at 1230?/1h/AC+850?/6h/FC,the volume fraction of the?₂/?lamella structure is reduced from 58%in the solid solution state to44%,and the size is increased from 48?m to 64?m;The volume fraction of?phase is increased from 35%in the solid solution state to 49%respectively,and the size is slightly increased;the room temperature yield strength of the alloy is increased from 519 MPa in the forged state to564 MPa.