Investigation On Microstructure And Mechanical Properity Of Ti-Fe-Cu-C Alloy

Titanium and its alloys are extensively applied into industrial circle for their excellent mechanical property,such as low density,high strength and good plasticity.Over the last few years,low cost and high strength Ti alloy has been an important issue in the field of research.According to the report,Ti-Fe system alloys exhibit a high fracture strength exceeding 2 GPa and good plasticity at room temperature compression tests.In this paper,taken Ti-Fe-Cu-C alloys as the project of research and additioned small amount of C element to improve the structure and property.Series of Ti-Fe-Cu-C alloys were prepared,the microstructure and mechanical property of cast and hot rolled state alloys were investigated.Master alloys were prepared by vacuum smelting equipment under argon atmosphere on a water-cooled Cu hearth.The composition,morphology,structure and fracture of samples were checked by a X-ray diffractometer,optical microscopy,the scanning electron microscopy,and transmission electron microscope.Room temperature mechanical properties were measured with an Instron-5982 testing machine.At first,Cast Ti_95-x(Fe_96.83C_3.17)_xCu₅?x=10,15,20,25 at.%?alloys contained ?-Ti solid solution,TiFe phase and rich titanium TiC.Under the compression tests,Ti70(Fe_96.83C_3.17)25Cu₅ and Ti75(Fe_96.83C_3.17)20Cu₅ reached extremely high yield strength 1962 and 1918 MPa respectively.Ti80(Fe_96.83C_3.17)15Cu₅ and Ti85(Fe_96.83C_3.17)10Cu₅ alloys achieved over 3GPa ultimate failure strength,3013 and 3090 MPa,with 25.57% and 35.30% compressive strain.Secondly,Ti₉₀(Fe_96.83C_3.17)₅Cu₅ alloy was rolled at 900?,850? and 800?.Matrix of the alloys were ?-Ti.Spherical ? phase emerged with the rolling temperature decrease.TiC became turning round under hot rolling.Tensile tests showed that tensile strength increased from 893 MPa to1289MPa and1282 MPa,plasticity increased from 0 to 1.50% and 1.89%.The simple rolling at 900? was annealing 30 min at 650?.Equiaxial ? phase precipitated in the grain boundary.Tensile strength achieved 1460 MPa with unchanged plasticity.At last,low-alloy Ti₉₄(Fe_96.83C_3.17)₃Cu₃ alloy was rolling at 850? and 800?,and the simple alloys were consist of ? and ? phase.The simple rolling at 850? showed excellent comprehensive performance with tensile strength 1095 Mpa and 5.04% ductility.