Investigation of Ti–Fe–Co bulk alloys with high strength and enhanced ductility

Abstract High-strength Ti–Fe–Co alloys were produced in the shape of arc-melted ingots with the dimensions of about 20–25 mm in diameter and 7–10 mm in height. The structure of the Ti–Fe–Co alloys (at Fe/Co ratio >1) studied by X-ray diffractometry and scanning electron microscopy consisted of an ordered Pm 3 ¯ m Ti(FeCo) compound and a disordered body-centered cubic Im 3 ¯ m β-Ti solid solution. The optimization of the Ti–Fe–Co alloy composition is performed from the viewpoint of both high strength and ductility. The strongest Ti–Fe–Co alloys have a hypereutectic structure and exhibit a high strength of about 2000 MPa and a plastic deformation of 15%. The high strength and ductility values can be achieved without using the injection mould casting or rapid solidification procedure. The deformation behavior and the fractography of Ti–Fe–Co alloys are studied in detail.