Microstructures and Mechanical Properties of Directionally Solidified Intermetallic Composites
This paper reviews two kinds of well-aligned fibrous microstructures produced by directional solidification of NiAl-Mo and Fe-Fe2Ta eutectics. In both these composites, fiber size and spacing decrese inversely as the square root of the growth rate. Tensile tests as a function of temperature showed that the NiAl-Mo composite has a higher yield strength and lower ductile-to-brittle transition temperature than the NiAl matrix. For the Fe-Fe2Ta composite, yield strengths in excess of 700 MPa were obtained at temperatures to 600°C, with elongations to fracture of ~3% which remained roughly constant at temperatures to 950°C.
T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran
H. Bei and E.P. George, "Microstructures and Mechanical Properties of Directionally Solidified Intermetallic Composites", Materials Science Forum, Vols. 539-543, pp. 1495-1500, 2007