Microstructure Evolution and Mechanical Properties of TC4 Alloy Prepared by Electron Beam Cold Hearth Furnace During Rolling Process

In this investigation, the effects of the different deformation degree and temperatures on the microstructure evolution and mechanical properties of TC4 titanium alloy fabricated by electron beam cold hearth melting (EBCHM) were investigated. The experimental results showed that as the deformation degree increased at the same temperature, the volume fractions and sizes of α phase were decreased while the volume fractions of β phase were increased, and the ultimate tensile strength (UTS) and ductility of this alloy were both increased. When the deformation degree was 30%, all the microstructures with different temperature were presented lamellar structures. As the deformation temperatures increased, the sizes of lamellar α phases were decreased and the UTS of this alloy were gradually increased while the ductility was changed a little. When the defor-mation degree was 90%, as the deformation temperatures increased the microstructures were changed from strong B textures (0002)<1120> into T texture(1010)<1120> and a small amount of pyramid texture(1011)<1120>, the plastic deformation was dominated by the cylindrical slip system and the base slip system. The sizes of α phase were decreased while the volume fractions of β phase were increased in these microstructures, and the UTS and ductility of this alloy were both increased. When the temperature increased to 1 000℃, α phases were fully transformed into β phases, the fine-secondary acicular α phases were precipitated from β phase matrix and the UTS and ductility of this alloy were both increased. © 2021, Materials Review Magazine. All right reserved.