Continuous Mo fiber reinforced Ti/Al3Ti metal-intermetallic laminated composites

Abstract

In this work, continuous Mo fiber as a reinforcement was introduced into Ti/Al3Ti metal-intermetallic-laminated (MIL) composite via vacuum hot pressing (VHP). In order to avoid excessive consumption of Mo fibers reacting with Al, and also obtain an appropriate amount of Al3Ti, a Ti foil with the thickness of 0.1 mm as an expendable was inserted between the Al foil and Mo fibers. The microstructure characterization of the MIL composite was performed via X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the tensile mechanical properties were measured by employing an Instron-5500R load frame. Results indicated that after VHP, the inserted thin Ti foils were completely depleted and converted into the dominant phase Al3Ti, which existed in the intermetallic layer. Four Al–Mo intermetallic, Al8Mo3, Al4Mo, Al5Mo and Al12Mo were successively formed around Mo fiber. The sequence of these Al–Mo intermetallic can be well explained by the thermodynamics calculation combined with the kinetic factor. Tensile tests show that when the arrangement of the fibers is parallel to the tensile direction, the introduction of Mo fibers significantly improves the tensile strength and strain to failure of the composite fibers, which is obviously related to the excellent mechanical properties of the Mo fibers themselves and their good bonding with the matrix.